NEED THE ANSWER PLS TIMER
Angela was given this expression to simplify. Negative 2 (2 x + 1) minus 3 (x + 3). Consider her steps in simplifying: 1. Negative 2 (2 x) + (negative 2) (1) + negative 3 (x) + (negative 3) (3). 2. Negative 4 x + negative 2 + negative 3 x + negative 9. 3. Negative 7 x minus 11.

Which statements are true about the steps Angela used? Check all that apply.

In step 1, she distributed –2 through the parentheses.

In step 1, she distributed 3 through the parentheses.

In step 2, she added the factor to the value inside the parentheses.

In step 2, she multiplied the factor to the value inside the parentheses.

In step 3, she combined like terms.

Answers

Answer 1

9514 1404 393

Answer:

In step 1, she distributed –2 through the parentheses.In step 1, she distributed 3 through the parentheses.In step 2, she multiplied the factor to the value inside the parentheses.In step 3, she combined like terms.

Step-by-step explanation:

In step 1 Angela used the distributive property to eliminate both sets of parentheses. In step 2, she found each of the products she indicated in step 1. In step 3, she combined like terms.

Answer 2

Answer:

the answer is a,d,e

Step-by-step explanation:


Related Questions


Solve for x using the quadratic formula x^2-6x +9=0

Answers

Answer:

3 both ways x = 3

EXPLANATION:

plug in inputs and do a little simplifying we get

x = 6 ± √(36-36) all of that over 2

So we simplify and we get 6±sqrt(0) / 2

Then we get 6/2 = 3

x-0 = x+0

thats why there is only one answer

Answer:

The value of X is 3

Step-by-step explanation:

x²-6x+9=0

x²- 3x - 3x + 9= 0

X(x-3) -3(x-3)=0

(x-3) (x-3)=0

(x-3)²=0

(x-3)=0

x-3 = 0

X= 3

Fertilizer: A new type of fertilizer is being tested on a plot of land in an orange grove, to see whether it increases the amount of fruit produced. The mean number of pounds of fruit on this plot of land with the old fertilizer was 380 pounds. Agriculture scientists believe that the new fertilizer may change the yield. State the appropriate null and alternative hypotheses.

Answers

Answer:

The null and alternative hypothesis for this problem are:

[tex]H_0:\mu=380\\\\H_a: \mu>380[/tex]

Step-by-step explanation:

The alternative hypothesis shows the claim of the researchers. In this case, that the new type of fertilizer significantly increase the actual yield with the old fertilizer:

[tex]H_a: \mu>380[/tex]

The null hypothesis is the hypothesis to be nullified, so it states that the claim is not true and the yield is the same (or, at least, not significantly higher) as with the old fertilizer:

[tex]H_0: \mu=380[/tex]

Which of the following points is in the solution set of y

Answers

Where is the picture

What is the difference?
х
4
x2-2x-15 x² + 2x-35
x2 + 3x+12
(x-3)(x-5)(x+7)
x(x+3-12)
(x+3)(x-5)(x+7)
x2 + 3x+12
(x+3)(x-5)(x+7)
x2 + 3x-12
(x+3)(x-5)(x+7)

Answers

The difference of the equation is A = ( x² - 3x - 12 ) / ( x + 3 ) ( x - 5 ) ( x + 7 )

What is an Equation?

Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.

It demonstrates the equality of the relationship between the expressions printed on the left and right sides.

Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.

Given data ,

Let the equation be represented as A

Now , the value of A is

Substituting the values in the equation , we get

Let the first equation be P = x / ( x² - 2x - 15 )

Let the second equation be Q = 4 / x² + 2x - 35 )

Now , A = P - Q

On simplifying , we get

A = x / ( x² - 2x - 15 ) - 4 / x² + 2x - 35 )

Taking the LCM , we get

A = x ( x + 7 ) - 4 ( x + 3 ) / ( x + 3 ) ( x - 5 ) ( x + 7 )

A = x² + 7x - 4x + 12 / ( x + 3 ) ( x - 5 ) ( x + 7 )

A = ( x² - 3x - 12 ) / ( x + 3 ) ( x - 5 ) ( x + 7 )

Therefore , the value of A is ( x² - 3x - 12 ) / ( x + 3 ) ( x - 5 ) ( x + 7 )

Hence , the equation is A = ( x² - 3x - 12 ) / ( x + 3 ) ( x - 5 ) ( x + 7 )

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Solve for x


There’s no options sorry ya’ll please answer I’m desperate

Answers

Answer & Step-by-step explanation:

The triangle shown is an isosceles triangles. Isosceles triangles have a pair of congruent angles which are found at the bottom. These angles are called the base angles. So, when you find the measurement of one of the base angles, then the other base angle will have the same measurement.

We can find the measurement of x by subtracting 130 from 180. We are doing this because all triangles have a sum measurement of 180°. After we do this, then we will divide that number by 2 to find the measurement of x.

180 - 130 = 50

Now, we divide 50 by 2.

50 ÷ 2 = 25

So, the measurement of x is 25°.

Which expression is a factor of 4q^2r^3s + 8qrs?

Answers

Answer:

: 4qrs • (qr2 + 2)

Step-by-step explanation:

Step by step solution :

Step 1 :

Equation at the end of step 1 :

((22q2 • r3) • s) + 8qrs

Pulling out like terms :

3.1 Pull out like factors :

4q2r3s + 8qrs = 4qrs • (qr2 + 2)

Final result :

4qrs • (qr2 + 2)

I am really soo sorry if the answer is wrong!

1. If the ratio of the ages of Kissi and Esinam is 3:5 and that of Esinam and Lariba is 3:5 and the sum of the ages of all 3 is 147 years, what is the age difference between oldest the
youngest?​

Answers

Answer:

Age difference between oldest the  youngest = 48 years

Step-by-step explanation:

Given: Ratio of ages of Kissi and Esinam is 3:5, ratios of ages of Esinam and Lariba is 3:5 and sum of the ages of all 3 is 147 years

To find: age difference between oldest the  youngest

Solution:

Let age of Lariba be x years

As ratios of ages of Esinam and Lariba is 3:5,

Age of Esinam = [tex]\frac{3}{5}x[/tex]  years

As ratio of ages of Kissi and Esinam is 3:5,

Age of Kissi = [tex](\frac{3}{5}) (\frac{3}{5}x)=\frac{9}{25}x[/tex] years

Sum of the ages of all 3 = 147 years

[tex]x+\frac{3}{5}x+\frac{9}{25}x=147\\ \frac{25x+15x+9x}{25}=147\\ x=\frac{147(25)}{49}=75[/tex]

Age of Lariba = x = 75 years

Age of Esinam = [tex]\frac{3}{5}(75)=45\,\,years[/tex]

Age of Kissi = [tex]\frac{9}{25}(75)=27\,\,years[/tex]

So,

Age difference between oldest the  youngest = 75 - 27 = 48 years

Find the area of the following square.
Write your answer in simplest form.
Be sure to include the correct unit in your answer.
4 1/2m​

Answers

Answer:

[tex]20.25 \: m^2[/tex]

Step-by-step explanation:

Use the formula for the area of a square.

[tex]A=s^2[/tex]

Where [tex]s=4.5[/tex]

[tex]s^2\\(4.5)^2\\20.25[/tex]

The area of the square is 20.25 square meters as per the concept of the square.

To find the area of a square, we need to square the length of one of its sides. In this case, the side length is given as 4 1/2 meters.

First, we need to convert the mixed number 4 1/2 into an improper fraction. We can rewrite it as 9/2.

Next, we square the side length:

[tex]\frac{9}{2}^2 = \frac{81}{4}[/tex].

To simplify the fraction, we can divide the numerator by the denominator:

81 ÷ 4 = 20 remainders 1.

Therefore, the area of the square is 20 1/4 square meters.

However, we can simplify the mixed number further. Since 4 can be divided by 4 and 1 can be divided by 4, we have:

20 1/4

= 20 + 1/4

= 20 + 1/4

= 20 + 0.25

= 20.25.

Therefore, the area of the square is 20.25 square meters.

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What is the value of y at the point where the graph of an equation crosses the x-axis?

Answers

Answer:

  0

Step-by-step explanation:

The x-axis corresponds to the line y = 0. All points on the x-axis have a y-value of zero.

A study was conducted on the amount of time drivers wait for a stoplight to change at a particular intersection. The amount of time spent by 300 drivers was recorded and the resulting data were used to create boxplot.

a. What is approximately the median amount of time spent at this traffic light?
b. The top 25% of drivers waited at least how long?
c. The mean amount of time spent at this traffic light was bigger or smaller than the median? Explain.

Answers

Answer:

a) Median amount of time that is spent is around 2.3, rounded to 2.

b) 4 unit time

c) Mean amount of time is bigger than the median.

Step-by-step explanation:

Find the given attachment.

Note: Complete Question, along with the diagram is added

Does the frequency distribution appear to have a normal​ distribution? Explain. Temperature ​(degrees​F) Frequency 35 dash 39 1 40 dash 44 4 45 dash 49 9 50 dash 54 13 Temperature ​(degrees​F) Frequency 55 dash 59 9 60 dash 64 2 65 dash 69 1 Choose the correct answer below. A. ​No, because the frequencies start​ low, proceed to one or two high​ frequencies, then decrease to a low​ frequency, and the distribution is not symmetric. B. ​No, because the frequencies start​ low, proceed to one or two high​ frequencies, then decrease to a low​ frequency, and the distribution is approximately symmetric. C. ​Yes, because the frequencies start​ low, proceed to one or two high​ frequencies, then increase to a​ maximum, and the distribution is not symmetric. D. ​Yes, because the frequencies start​ low, proceed to one or two high​ frequencies, then decrease to a low​ frequency, and the distribution is approximately symmetric.

Answers

Answer:

D. ​Yes, because the frequencies start​ low, proceed to one or two high​ frequencies, then decrease to a low​ frequency, and the distribution is approximately symmetric.

Step-by-step explanation:

Hello!

The given frequency distribution for temperatures.

To see if the distribution appears to have a normal distribution you have to draw a histogram using the information. Check attachment.

As you can see, the distribution appears symmetric, it starts low and proceeds to grow until it reaches its maximum point (f(4)=13) and then starts to decrease to low frequencies. The right tail decreases a little more than the left one but it is almost symmetrical.

I hope this helps!

The market and Stock J have the following probability distributions:
Probability rM rJ
0.3 14% 22%
0.4 10 4
0.3 19 12
1. Calculate the expected rate of return for the market. Round your answer to two decimal places.%
2. Calculate the expected rate of return for Stock J. Round your answer to two decimal places.%
3. Calculate the standard deviation for the market. Round your answer to two decimal places.%
4. Calculate the standard deviation for Stock J. Round your answer to two decimal places.%

Answers

Answer:

1) [tex] E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%[/tex]

2) [tex]E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%[/tex]

3) [tex] E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1 [/tex]

And the variance would be given by:

[tex]Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{13.89}= 3.73[/tex]

4) [tex] E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8 [/tex]

And the variance would be given by:

[tex]Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{55.56}= 7.45[/tex]

Step-by-step explanation:

For this case we have the following distributions given:

Probability  M   J

0.3           14%  22%

0.4           10%    4%

0.3           19%    12%

Part 1

The expected value is given by this formula:

[tex] E(X)=\sum_{i=1}^n X_i P(X_i)[/tex]

And replacing we got:

[tex] E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%[/tex]

Part 2

[tex]E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%[/tex]

Part 3

We can calculate the second moment first with the following formula:

[tex] E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1 [/tex]

And the variance would be given by:

[tex]Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{13.89}= 3.73[/tex]

Part 4

We can calculate the second moment first with the following formula:

[tex] E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8 [/tex]

And the variance would be given by:

[tex]Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{55.56}= 7.45[/tex]

Solve for x in the equation x 2 - 4 x - 9 = 29.

Answers

Answer:

x= -19

Step-by-step explanation:

2x-4x-9=29

-2x=29+9

x=38/-2

= -19

Answer:

[tex]x=2-\sqrt{42}[/tex] and [tex]x=2+\sqrt{42} \\[/tex]

Step-by-step explanation:

Solve using the quadratic formula, which is [tex]x=\frac{-b + \sqrt{b^{2}-4ac }}{2a}[/tex] and [tex]x=\frac{-b-\sqrt{b^{2}-4ac } }{2a}[/tex]

Many students brag that they have more than 150 friends on a social media website. For a class​ project, a group of students asked a random sample of 13 students at their college who used the social media website about their number of friends and got the data available below. Is there strong evidence that the mean number of friends for the student population at the college who use the social media website is larger than 150?

Required:
a. Find and interpret the test statistic value.
b. Report and interpret the P-value and state the conclusion in context. Use a significance level of 0.05.
c. What does the test statistic value represent?

1. The test statistic value is the difference between the sample mean and the null hypothesis value.
2. The test statistic value is the number of standard errors from the null hypothesis value to the sample mean.
3. The test statistic value is the expected mean of the differences between the sample data and the null hypothesis value.
4. The test statistic value is the number of standard deviations from the null hypothesis value to the sample mean.

Answers

Answer:

Step-by-step explanation:

The question is incomplete. The missing data is:

30, 155, 205, 235, 180, 235, 70, 250, 135, 145, 225, 230, 30

Solution:

Mean = (30 + 155 + 205 + 235 + 180 + 235 + 70 + 250 + 135 + 145 + 225 + 230 + 30)/13 = 163.5

Standard deviation = √(summation(x - mean)²/n

n = 13

Summation(x - mean)² = (30 - 163.5)^2 + (155 - 163.5)^2 + (205 - 163.5)^2+ (235 - 163.5)^2 + (180 - 163.5)^2 + (235 - 163.5)^2 + (70 - 163.5)^2 + (250 - 163.5)^2 + (135 - 163.5)^2 + (145 - 163.5)^2 + (225 - 163.5)^2 + (230 - 163.5)^2 + (30 - 163.5)^2 = 73519.25

Standard deviation = √(73519.25/13) = 75.2

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

µ ≤ 150

For the alternative hypothesis,

µ > 150

It is a right tailed test.

a) Since the number of samples is small and no population standard deviation is given, the distribution is a student's t.

Since n = 13,

Degrees of freedom, df = n - 1 = 13 - 1 = 12

t = (x - µ)/(s/√n)

Where

x = sample mean = 163.5

µ = population mean = 150

s = samples standard deviation = 75.2

t = (163.5 - 150)/(75.2/√13) = 0.65

The lower the test statistic value, the higher the p value and the higher the possibility of accepting the null hypothesis.

b) We would determine the p value using the t test calculator. It becomes

p = 0.26

Since alpha, 0.05 < than the p value, 0.26, then we would fail to reject the null hypothesis. Therefore, At a 5% level of significance, the sample data does not show significant evidence that the mean number of friends for the student population at the college who use the social media website is larger than 150.

c)

1.The test statistic value is the difference between the sample mean and the null hypothesis value.

A company is constructing an​ open-top, square-based, rectangular metal tank that will have a volume of 49 cubic feet. What dimensions yield the minimum surface​ area? Round to the nearest tenth.

Answers

Answer:

b = 4.6 ft

h = 2.3 ft

Step-by-step explanation:

The volume of the tank is given by:

[tex]b^2*h=49[/tex]

Where 'b' is the length of the each side of the square base, and 'h' is the height of the tank.

The surface area can be written as:

[tex]A=b^2+4bh\\A=b^2+4b*({\frac{49}{b^2}})\\A=b^2+\frac{196}{b}[/tex]

The value of b for which the derivate of the expression above is zero is the value that yields the minimum surface area:

[tex]\frac{dA}{db} =0=2b-\frac{196}{b^2}\\2b^3=196\\b=4.61\ ft[/tex]

The value of h is then:

[tex]h=\frac{49}{4.61^2}\\h=2.31\ ft[/tex]

Rounded to the nearest tenth, the dimensions are b = 4.6 ft and h = 2.3 ft.

In a college of exactly 2800 students, exactly 55 % are male. What is the number of female students? Express your answer as an integer.

Answers

1260 students are female

(07.01 MC)Of the following sets, which numbers in {0, 1, 2, 3, 4} make the inequality 7x + 3 < 17 true? {0} {0, 1} {0, 1, 2} {2, 3, 4}

Answers

Answer:

{0, 1}

Step-by-step explanation:

Solving for 'x' in the inequality:

[tex]7x+3<17\\7x+3-3<17-3 \leftarrow \text{Subtraction Property of Equality}\\7x<14\\7x/7<14/7 \leftarrow \text{Division Property of Equality}\\\boxed{x<2}[/tex]

X's value has to be less than two to make the inequality true. So, {0, 1} should be the correct answer.

Answer:

I took the quiz and the answer is B

Step-by-step explanation:

Suppose we are interested in bidding on a piece of land and we know one other bidder is interested. The seller announced that the highest bid in excess of $10,400 will be accepted. Assume that the competitor's bid x is a random variable that is uniformly distributed between $10,400 and $15,400.

Required:
a. Suppose you bid $12,000. What is the probability that your bid will be accepted (to 2 decimals)?
b. Suppose you bid $14,000. What is the probability that your bid will be accepted (to 2 decimals)?
c. What amount should you bid to maximize the probability that you get the property (in dollars)?

Answers

Answer:

a) 0.32 = 32% probability that your bid will be accepted

b) 0.72 = 72% probability that your bid will be accepted

c) An amount in excess of $15,400.

Step-by-step explanation:

An uniform probability is a case of probability in which each outcome is equally as likely.

For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.

The probability that we find a value X lower than x is given by the following formula.

[tex]P(X \leq x) = \frac{x - a}{b-a}[/tex]

Assume that the competitor's bid x is a random variable that is uniformly distributed between $10,400 and $15,400.

This means that [tex]a = 10400, b = 15400[/tex]

a. Suppose you bid $12,000. What is the probability that your bid will be accepted (to 2 decimals)?

You will win if the competitor bids less than 12000. So

[tex]P(X \leq 12000) = \frac{12000 - 10400}{15400 - 10400} = 0.32[/tex]

0.32 = 32% probability that your bid will be accepted

b. Suppose you bid $14,000. What is the probability that your bid will be accepted?

You will win if the competitor bids less than 14000. So

[tex]P(X \leq 14000) = \frac{14000 - 10400}{15400 - 10400} = 0.72[/tex]

0.72 = 72% probability that your bid will be accepted

c. What amount should you bid to maximize the probability that you get the property (in dollars)?

His bid is uniformly distributed between $10,400 and $15,400.

So, to maximize the probability that you get the property, you should bid an amount in excess of $15,400.

Please answer this correctly

Answers

Answer:

# of pages   # of magazines

     1-20                    7

   21-40                    4

Step-by-step explanation:

Numbers 1 through 20:

10, 11, 14, 16, 17, 17, 20 (7 numbers)

Numbers 21 through 40:

21, 28, 29, 32 (4 numbers)

a courtroom spectator merely looks at the defendant and says, “He’s guilty, i tell you.”

Answers

Answer:

hes lyin prolly

Step-by-step explanation:

Hahahahahahaha imagine

The mean height of women in a country​ (ages 20minus​29) is 64.2 inches. A random sample of 75 women in this age group is selected. What is the probability that the mean height for the sample is greater than 65 ​inches? Assume sigmaequals2.84. The probability that the mean height for the sample is greater than 65 inches is nothing.

Answers

Answer:

[tex] z=\frac{65-64.2}{\frac{2.84}{\sqrt{75}}} = 2.440[/tex]

And we can find the probability using the complement rule and with the normal standard table like this:

[tex] P(Z>2.440) =1-P(Z<2.440) = 1-0.993 =0.007[/tex]

The probability that the mean height for the sample is greater than 65 inches is 0.007

Step-by-step explanation:

Let X the random variable that represent the women heights of a population, and we know the following parameters

[tex]\mu=64.2[/tex] and [tex]\sigma=2.84[/tex]

We are interested on this probability

[tex]P(X>65)[/tex]

Since the sample size selected is 75>30 we can use the centrel limit theorem and the appropiate formula to use would be the z score given by:

[tex]z=\frac{x-\mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

If we find the z score for 65 inches we got:

[tex] z=\frac{65-64.2}{\frac{2.84}{\sqrt{75}}} = 2.440[/tex]

And we can find the probability using the complement rule and with the normal standard table like this:

[tex] P(Z>2.440) =1-P(Z<2.440) = 1-0.993 =0.007[/tex]

The probability that the mean height for the sample is greater than 65 inches is 0.007

Find the exact solution of 3x^2+7=28

Answers

[tex]\text{Solve:}\\\\3x^2+7=28\\\\\text{Subtract 7 from both sides}\\\\3x^2=21\\\\\text{Divide both sides by 3}\\\\x^2=7\\\\\text{Square root both sides}\\\\\sqrt{x^2}=\sqrt7\\\\x=\pm\sqrt7\\\\\boxed{x=\sqrt7\,\,or\,\,x=-\sqrt7}[/tex]

The figure shows three lines that intersect at point N.

3 lines intersect. Lines G K and J M intersect at point N to form a right angle. Line H L intersects the other lines at point N. Angle H N G is 48 degrees.
Angle GNH is congruent to angle KNL. Angle MNL is complementary to angle KNL. What is the measure of angle MNL?

42°
48°
132°
138°

Answers

Answer

The figure shows three lines that intersect at point N.

3 lines intersect. Lines G K and J M intersect at point N to form a right angle. Line H L intersects the other lines at point N. Angle H N G is 48 degrees.

Angle GNH is congruent to angle KNL. Angle MNL is complementary to angle KNL. What is the measure of angle MNL?

42°

48°

132°

138°

Step-by-step explanation:

42

The required measure of angle MNL is 42°. Option A is correct.

3 lines intersect lines G K and J M intersect at point N to form a right angle. Line H L intersects the other lines at point N. Angle H N G is 48 degrees. Angle GNH is congruent to angle KNL. Angle MNL is complementary to angle KNL. What is the measure of angle MNL is to determine

What is the angle?

The angle can be defined as the one line inclined over another line.
unit of measure of an angle is degree and radians.

Angle GNH is congruent to angle KNL.
∠KNL = 48°
Angle MNL is complementary to angle KNL
Since angle MNK = 90°
∠MNL + ∠KNL = 90°

∠MNL = 90-48
∠MNL = 42°

Thus, the required measure of angle MNL is 42°. Option A is correct.

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For the given set, first calculate the number of subsets for the set, then calculate the
{5, 13, 17, 20}
The number of subsets is ]
The number of proper subsets is .

Answers

Answer:

[tex]\fbox{\begin{minipage}{14em}Number of subsets: 16\\Number of proper subsets: 15\end{minipage}}[/tex]

Step-by-step explanation:

Given:

The set A = {5, 13, 17, 20}

Question:

Find the number of subsets of A

Find the number of proper subsets of A

Simple solution by counting:

Subset of A that has 0 element:

{∅} - 1 set

Subset of A that has 1 element:

{5}, {13}, {17}, {20} - 4 sets

Subset of A that has 2 elements:

{5, 13}, {5, 17}, {5, 20}, {13, 17}, {13, 20}, {17, 20} - 6 sets

Subset of A that has 3 elements:

{5, 13, 17}, {5, 13, 20}, {5, 17, 20}, {13, 17, 20} - 4 sets

Subset of A that has 4 elements:

{5, 13, 17, 20} - 1 set

In total, the number of subsets of A: N = 1 + 4 + 6 + 4 + 1 = 16

The number of proper subsets (all of subsets, except subset which is equal to original set A): N = 16 - 1 = 15

Key-point:

The counting method might be used for finding the number of subsets when the original set contains few elements.

The question is that, for a set that contains many elements, how to find out the number of subsets?

The answer is that: there is a fix formula to calculate the total number ([tex]N[/tex]) of subsets of a set containing [tex]n[/tex] elements: N = [tex]2^{n}[/tex]

With original set A = {5, 13, 17, 20}, there are 4 elements belonged to A.

=> Number of subsets of A: N = [tex]2^{4} = 16[/tex]

(same result as using counting method)

Brief proof of formula: N = [tex]2^{n}[/tex]

Each element of original set is considered in 2 status: existed or not.

If existed => fill that element in.

If not => leave empty.

For i.e.: empty subset means  that all elements are selected as not existed, subset with 1 element means that all elements are selected as not existed, except 1 element, ... and so on.

=> From the point of view of a permutation problem, for each element in original set, there are 2 ways to select: existed or not. There are [tex]n[/tex] elements in total. => There are [tex]2^n}[/tex] ways to select, or in other words, there are [tex]2^{n}[/tex] subsets.

Hope this helps!

:)

A recent graduate school study of a random sample of 250 US manufacturing companies determined the average financial report preparation time was 68.04 days with a standard deviation of 35.74 days. Calculate to three decimal places the 95 percent confidence interval for the mean report prep time for all US manufacturing companies. [63.001, 72.008] [63.957, 75.568] [63.505, 72.414] [61.612, 74.468] [63.612, 72.468]

Answers

Answer:

[tex]68.04-1.959\frac{35.74}{\sqrt{250}}=63.618[/tex]    

[tex]68.04+1.959\frac{35.74}{\sqrt{250}}=72.461[/tex]    

And the best option for this case would be

Step-by-step explanation:

Information given

[tex]\bar X=68.04[/tex] represent the sample mean

[tex]\mu[/tex] population mean

s=35.74 represent the sample standard deviation

n=250 represent the sample size  

Confidence interval

The confidence interval for the mean is given by the following formula:

[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex]   (1)

The degrees of freedom are given by:

[tex]df=n-1=250-1=249[/tex]

The Confidence level is 0.95 or 95%, and the significance [tex]\alpha=0.05[/tex] and [tex]\alpha/2 =0.025[/tex], and the critical value for this case woud be [tex]t_{\alpha/2}=1.956[/tex]

And replacing we got:

[tex]68.04-1.959\frac{35.74}{\sqrt{250}}=63.618[/tex]    

[tex]68.04+1.959\frac{35.74}{\sqrt{250}}=72.461[/tex]    

And the best option for this case would be

45 units and is centered at


A circle has a radius of


(-2.4, -4.8).


What is the equation of this circle?

Answers

The correct question is:

A circle has a radius of 45 units and is centered at (-2.4, -4.8).

What is the equation of this circle?

Answer:

Equation of the circle is;

(x + 2.4)² + (y + 4.8)² = 2304

Step-by-step explanation:

The standard equation of a circle is;

(x - a)² + (y - b)²  =  r²

where;

(a,b) is the center of the circle and r is the radius of the circle

Now, from the question, the circle is centered at (-2.4, -4.8) and the radius is 45

Thus, plugging those values into the standard form of equation of a circle, we have;

(x - (-2.4))²  +  (y - (-4.8))²  = 48²

This gives;

(x + 2.4)² + (y + 4.8)² = 2304

What is the height of a sphere of radius 6 inches?

Answers

Answer:

12 inches.

Step-by-step explanation:

The height of a sphere = the length of its diameter.

Diameter = 2 * radius = 12 ins.

In determining automobile-mileage ratings, it was found that the mpg (X) for a certain model is normally distributed, with a mean of 33 mpg and a standard deviation of 1.7 mpg. Find the following:__________.
a. P(X<30)
b. P(28 c. P(X>35)
d. P(X>31)
e. the mileage rating that the upper 5% of cars achieve.

Answers

Answer:

a) P(X < 30) = 0.0392.

b) P(28 < X < 32) = 0.2760

c) P(X > 35) = 0.1190

d) P(X > 31) = 0.8810

e) At least 35.7965 mpg

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 33, \sigma = 1.7[/tex]

a. P(X<30)

This is the pvalue of Z when X = 30. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{30 - 33}{1.7}[/tex]

[tex]Z = -1.76[/tex]

[tex]Z = -1.76[/tex] has a pvalue of 0.0392.

Then

P(X < 30) = 0.0392.

b) P(28 < X < 32)

This is the pvalue of Z when X = 32 subtracted by the pvalue of Z when X = 28. So

X = 32

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{32 - 33}{1.7}[/tex]

[tex]Z = -0.59[/tex]

[tex]Z = -0.59[/tex] has a pvalue of 0.2776.

X = 28

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{28 - 33}{1.7}[/tex]

[tex]Z = -2.94[/tex]

[tex]Z = -2.94[/tex] has a pvalue of 0.0016.

0.2776 - 0.0016 = 0.2760.

So

P(28 < X < 32) = 0.2760

c) P(X>35)

This is 1 subtracted by the pvalue of Z when X = 35. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{35 - 33}{1.7}[/tex]

[tex]Z = 1.18[/tex]

[tex]Z = 1.18[/tex] has a pvalue of 0.8810.

1 - 0.8810 = 0.1190

So

P(X > 35) = 0.1190

d. P(X>31)

This is 1 subtracted by the pvalue of Z when X = 31. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{31 - 33}{1.7}[/tex]

[tex]Z = -1.18[/tex]

[tex]Z = -1.18[/tex] has a pvalue of 0.1190.

1 - 0.1190 = 0.8810

So

P(X > 31) = 0.8810

e. the mileage rating that the upper 5% of cars achieve.

At least the 95th percentile.

The 95th percentile is X when Z has a pvalue of 0.95. So it is X when Z = 1.645. Then

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.645 = \frac{X - 33}{1.7}[/tex]

[tex]X - 33 = 1.645*1.7[/tex]

[tex]X = 35.7965[/tex]

At least 35.7965 mpg

The upper 5% of cars have a mileage rating of 35.805 mpg

What is z score?

Z score is used to determine by how many standard deviations the raw score is above or below the mean. It is given by:

z = (raw score - mean) / standard deviation

Given;  mean of 33 mpg and a standard deviation of 1.7

a) For < 30:

z = (30 - 33)/1.7 = -1.76

P(x < 30) = P(z < -1.76) = 1 - 0.8413 = 0.0392

b) For < 28:

z = (28 - 33)/1.7 = -2.94

P(x < 28) = P(z < -2.94) = 0.0016

c) For > 35:

z = (35 - 33)/1.7 = 1.18

P(x > 35) = P(z > 1.18) = 1 - P(z < 1.18) = 1 - 0.8810 = 0.119

d) For > 31:

z = (31 - 33)/1.7 = -1.18

P(x > 31) = P(z > -1.18) = 1 - P(z < -1.18) = 0.8810

e) The  upper 5% of cars achieve have a z score of 1.65, hence:

1.65 = (x - 33)/1.7

x = 35.805 mpg

The upper 5% of cars have a mileage rating of 35.805 mpg

Find out more on z score at: https://brainly.com/question/25638875

1) Ethan, Amir, Victoria, and Kayla share
3 apples equally. What fraction of an
apple does each friend get?​

Answers

Answer:

3 apples / 4 people

3/4

to check divide fractions

Multiply reciprocal

3/1 x 4/1

3/1 / 1/4 = 3/4

3/4 x 4 = 12/4 = 3 apples

3/4 is the answer

Hope this helps

Step-by-step explanation:

from a deck of 52 cards, what is the probability of getting a four or diamond.

Answers

Answer:

4/13

Step-by-step explanation:

There are 13 diamonds in a deck and 3 fours that aren't diamond

13+3=16

16/52 = 4/13

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