.
A students received a score of 50 on his history test. The test had a mean of 69 and a standard deviation of 10. Find the z score and assess whether his score is considered unusual.

1.90; unusual

–1.90; not unusual

–1.90; unusual

1.90; not unusual

Answer:

The approximate probability that more than six students were born on Christmas day is P=0.105.

Step-by-step explanation:

This can be modeled as a binomial variable, with n=1460 and p=1/365.

The sample size n is the total amount of students and the probability of success p is the probability of each individual of being born on Christmas day.

As the sample size is too large to compute it as a binomial random variable, we approximate it to the normal distribution with the following parameters:

[tex]\mu=n\cdot p=1460\cdot (1/365)=4\\\\\sigma=\sqrt{n\cdot p(1-p)}=\sqrt{1460\cdot(1/365)\cdot(364/365)}=\sqrt{3.989}=1.997[/tex]

We want to calculate the probability that more than 6 students were born on Christmas day. Ww apply the continuity factor and we write the probability as:

[tex]P(X>6.5)[/tex]

We calculate the z-score for X=6.5 and then calculate the probability:

[tex]z=\dfrac{X-\mu}{\sigma}=\dfrac{6.5-4}{1.997}=\dfrac{2.5}{1.997}=1.252\\\\\\P(X>6.5)=P(z>1.252)=0.105[/tex]

Answer:144 sweets

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

Length × Width = Area

So we'll substitute the Area of the circle having formula, πr²

Answer:

25

Step-by-step explanation:

I'm going with $25 since socks should cost as much as underwear, you wear them underneath and they're an essential.

Answer: -1

Step-by-step explanation:

You want to find an angle that is coterminal to 495. So, subtract 360 degrees until youre in the range of 0-360. I got 495 - 360 = 135°

Tangent is equal to [tex]\frac{sin(theta)}{cos(theta)}[/tex], we already solved theta which was 135°

This next part is hard to explain to someone who doesnt know their trig circle, idk if you do. The angle 135 is apart of the pi/4 gang. So we know this is going to be some variant of √2/2. Sine of quadrant 1 and 2 is gonna be positive:

[tex]sin135=\frac{\sqrt{2} }{2}[/tex]

Now lets do cosine of 135°, which again is apart of the pi/4 gang because its divisible by 45°. Its in quadrant 2 so the cosine will be negative.

[tex]cos135=-\frac{\sqrt{2} }{2}[/tex]

The final step is to divide them. They are both fractions so you should multiply by the reciprocal.

[tex]\frac{\sqrt{2} }{2} *-\frac{2}{\sqrt{2} } =-\frac{2\sqrt{2} }{2\sqrt{2} } =-1[/tex]

Answer:

The answer is No Solution

Answer:

No solution

Step-by-step explanation:

There is no solution to this question.

Since the x is an absolute number, the answer cannot be -4. It would have to equal 4

So if that x was a -4 it would equal 4 since it is in absolute value brackets

Answer:

207.24cm

Step-by-step explanation:

Circumference=2pi*r

=2 (3.14)(33)

=207.24cm

The circumference of the circle is 103.62 cm².

Given that, a circle with diameter of 33 cm.

Radius=d/2=16.5 cm.

The formula to find the circumference of the circle is 2πr.

Now, 2×3.14×16.5=103.62 cm².

Therefore, the circumference of the circle is 103.62 cm².

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Answer:

  ∠F ≈ 43.9°

Step-by-step explanation:

The Law of Cosines is used to find an angle when all triangle sides are known.

  f² = d² +e² -2de·cos(F)

  cos(F) = (d² +e² -f²)/(2de) = (25² +28² -20²)/(2·25·28) = 1009/1400

  F = arccos(1009/1400)

  F ≈ 43.9°

Answer:

2

Step-by-step explanation:

Set the height of the bar to 2 since there are 2 numbers between 21-40.

Answer:

2 people.

Step-by-step explanation:

34 minutes and 40 minutes were recorded.

Therefore, 2 people.

Answer:

Coefficient of variation (weight) = 15%

Coefficient of variation (volume) = 25%

Step-by-step explanation:

Let's begin by listing out the given information:

Population = 200, Average weight = 26 lb,

standard deviation (weight) = 3.9 lb,

Average volume = 8.8 ft³,

standard deviation (volume) = 2.2 ft³

Based on the data given, the manager will have to make a deduction by comparing the relative scatter of both variables due to the different units of measuring weight (pounds) and volume (cubic feet).

To compare the variation of the weight and volume, we use the coefficient of variation given by the formula:

Coefficient of Variation = (Standard deviation ÷ Mean) * 100%

⇒ [tex]C_{v}[/tex] = (σ ÷ μ) * 100%

For weight

σ = 3.9 lb, μ = 26 lb

[tex]C_{v}[/tex] (weight) = (3.9 ÷ 26.0) * 100% = 15%

[tex]C_{v}[/tex] (weight) = 15%

For volume

σ = 2.2 ft³, μ = 8.8 ft³

[tex]C_{v}[/tex] (volume) = (2.2 ÷ 8.8) * 100% = 25%

[tex]C_{v}[/tex] (volume) = 25%

∴ the relative variation of the volume of the package is greater than that of the weight of the package

Answer:

Step-by-step explanation:

The question is incomplete. The complete question is:

Eagle Outfitters is a chain of stores specializing in outdoor apparel and camping gear. It is considering a promotion that involves mailing discount coupons to all its credit card customers. This promotion will be considered a success if more than 10% of those receiving the coupons use them. Before going national with the promotion, coupons were sent to a sample of 100 credit card customers. Out of the 100 customers, 13 customers said that they used the discount coupons to make a purchase at a Eagle Outfitters store. Use a 0.05 level of significance. (a) Develop the null and alternative hypotheses that can be used to test whether the population proportion of those who will use the coupons is sufficient to go national. (b) Compute the sample proportion. (c) Compute the test statistic. (d) Compute the critical value. (e) Based on the critical value, do we reject H0 or do we not reject H0? (f) Based on the result of the hypothesis test, should Eagle Outfitter go national with the promotion?

Solution:

a) We would set up the hypothesis test.

For the null hypothesis,

H0: p ≥ 0.1

For the alternative hypothesis,

Ha: p < 0.1

This is a left tailed test

Considering the population proportion, probability of success, p = 0.1

q = probability of failure = 1 - p

q = 1 - 0.1 = 0.9

b) Considering the sample,

Sample proportion, P = x/n

Where

x = number of success = 13

n = number of samples = 100

p = 13/100 = 0.13

c) We would determine the test statistic which is the z score

z = (P - p)/√pq/n

z = (0.13 - 0.1)/√(0.1 × 0.9)/100 = 1

The calculated test statistic is 1 for the right tail and - 1 for the left tail.

d) Since α = 0.05, the critical value is determined from the normal distribution table.

For the left, α/2 = 0.51/2 = 0.025

The z score for an area to the left of 0.025 is - 1.96

For the right, α/2 = 1 - 0.025 = 0.975

The z score for an area to the right of 0.975 is 1.96

e) In order to reject the null hypothesis, the test statistic must be smaller than - 1.96 or greater than 1.96

Since - 1 > - 1.96 and 1 < 1.96, we would fail to reject the null hypothesis.

Therefore, based on the result of the hypothesis test, the Eagle Outfitter should go national with the promotion

Answer:

[tex]t \approx 17.690\,min[/tex]

Step-by-step explanation:

This differential equation is a first order linear differential equation with separable variables, whose solution is found as follows:

[tex]\frac{dy}{dt} = - \frac{1}{53} \cdot (y - 17)[/tex]

[tex]\frac{dy}{y-17} = -\frac{1}{53} \, dt[/tex]

[tex]\int\limits^{y}_{y_{o}} {\frac{dy}{y-17} } = -\frac{1}{53} \int\limits^{t}_{0}\, dx[/tex]

[tex]\ln \left |\frac{y-17}{y_{o}-17} \right | = -\frac{1}{53} \cdot t[/tex]

[tex]\frac{y-17}{y_{o}-17} = e^{-\frac{1}{53}\cdot t }[/tex]

[tex]y = 17 + (y_{o} - 17) \cdot e^{-\frac{1}{53}\cdot t }[/tex]

The solution of the differential equation is:

[tex]y = 17 + 74\cdot e^{-\frac{1}{53}\cdot t }[/tex]

Where:

[tex]y[/tex] - Temperature, measured in °C.

[tex]t[/tex] - Time, measured in minutes.

The time when the cup of coffee has the temperature of 70 °C is:

[tex]70 = 17 + 74 \cdot e^{-\frac{1}{53}\cdot t }[/tex]

[tex]53 = 74 \cdot e^{-\frac{1}{53}\cdot t }[/tex]

[tex]\frac{53}{74} = e^{-\frac{1}{53}\cdot t }[/tex]

[tex]\ln \frac{53}{74} = -\frac{1}{53}\cdot t[/tex]

[tex]t = - 53\cdot \ln \frac{53}{74}[/tex]

[tex]t \approx 17.690\,min[/tex]

Answer:

The one with the better deal would be 30 ride tickets for $22.50 this is because you pay less money for more rides.

Step-by-step explanation:

First you divide 20 by 14. Doing this will give you the cost of a ride per ticket.

20/14 = 1.42

Then you do the same thing to 30 and 22.50.

30/22.50 = 1.30

Last you compare which deal has less money per ride.

1.42 > 1.30

Answer:

You are 6

Step-by-step explanation:

8×6=48 and 6/3=2

6 is even and fits in all of these areas.

Hope this helps.

Mark brainliest if correct.

Answer:

they played the pivotal role

Answer:

⬇⬇⬇⬇⬇⬇

⬇⬇⬇⬇⬇⬇

Step-by-step explanation:

1, 3, 4

proof below

(1) The area of the rectangle is 88 square inches

(3) The equation x² – 3x – 88 = 0 can be used to solve for the length of the rectangle.

(4) The triangle has a base of 11 inches and a height of 8 inches.

Area of a rectangle is the sum of the area of two equal right triangle.

Area of rectangle = 2(area of right triangle)

Area of rectangle = 2(44 sq inches) = 88 sq inches

Let the length = x

then the width becomes, x - 3

Area = x(x - 3) = 88

x² - 3x = 88

x² - 3x - 88 = 0

x = 11

width = 11 - 3 = 8

Thus, the statements that are true include;

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Answer:2x−5=−5

Add 5

to both sides of the equation.

2x=−5+5

Add −5

and 5

.

2x=0

Divide each term by 2

and simplify.

Divide each term in 2x=0

by 2

.

2x2=02

Cancel the common factor of 2

.

Cancel the common factor.

2

x2=02

Step-by-step explanation:

Apply the distributive property.

x⋅2+2⋅2−9=−5

Move 2

to the left of x

.

2⋅x+2⋅2−9=−5

Multiply 2

by 2

.

2x+4−9=−5

Subtract 9

from 4

.

The right answer is of option D.

[tex]x \geqslant 4[/tex]

In the given graph, X is greater than 4 and X equals to 4.

Hope it helps.....

Good luck on your assignment

Answer:

Step-by-step explanation:

Hello!

The variable is

X: average mass of a sample of rocks collected in the waters of a region. (measured in grams)

Variables can be:

Quantitative: they represent number, any characteristic that can be "counted" is a quantitative variable, the most common examples are weight, volume, temperature, height, etc...

There are two types of quantitative variables:

⇒ Discrete variables: The only take certain values within the interval of definition of the variable, for example "number of sales" or "money in a wallet"

⇒ Continuous variables: They can take any value within an interval, in this example that you are working with mass, depending on the precision of the scale the mass can have infinite decimal values.

Qualitative: they represent characteristics that cannot be counted, meaning, they are not represented by numbers. There are many attributes that are qualitative variables, for example: colors, race of an animal, phenotypes, types of business, etc...

1)

The variable in this example is Quantitative, it takes numerical values, and the correct option is:

D. Quantitative, because numerical values, found by either measuring or counting, are used to describe the data.

2)

The values of mass of the rocks can take any value within the range of definition of the variable, they only depend on the precision of the scale used to weight the rocks.

B. Interval, because the differences in the data can be meaningfully measured, but the data do not have a true zero point.

3)

A standard 52-card deck contains 13 cards for each suit (clubs, diamonds, hearts and spades)

To calculate the probability of choosing a card at random and it being a Diamond, supposing that all cards are equally probable, you have to divide the total number of diamonds by the total number of cards in the deck:

P(diamond)= 13/52= 0.25

For items 4) and 5) the contingency tables are attached.

4)

a. and b. are conditional probabilities, to calculate them you have to apply the following formula: [tex]P(A|B)= \frac{P(AnB)}{P(B)}[/tex]

This means that the probability of the event "A" given that event "B" has occurred is equal to the probability of the intersection between events "A" and "B" divided by the probability of event "B"

a. P(A|C)= [tex]\frac{P(AnC)}{P(C)}[/tex]

To calculate the probability of the intersection P(A∩C) you have to divide the observations where both events cross by the total of observations on the table:

P(A∩C)= 10/50= 0.20

The probability of C is found in the margins of the table, in this case you have to divide the total of observations for event C by the total of observations of the table:

P(C)= 21/50= 0.42

Now you can calculate the asked probability:

[tex]P(A|C)= \frac{0.2}{0.42}= 0.48[/tex]

b. P(C|A)= [tex]\frac{P(AnC)}{P(A)}[/tex]

From item a. we already know that P(A∩C)= 10/50= 0.20

The probability of event A is  in the margin of the table and you calculate it as:

P(A)= 27/50= 0.54

Then:

[tex]P(C|A)= \frac{0.20}{0.54} = 0.37[/tex]

c. P(BE)

This symbolized the probability of the events "B" and "E" occurring at the same time, you can also symbolize it as P(B∩E)

To calculate the probability of B and E happening you have to do as follows:

P(B∩E)= 8/50= 0.16

5)

a. P(C|A)= 0.37 (As calculated in 4b.)

b. P(BE) and c. P(EB) ⇒ Both expressions symbolize the intersection between events "B" and "E", P(B∩E)= P(E∩B)= 0.16 (As calculated in 4c.)

I hope this helps!

Answer:

32 cm²

Step-by-step explanation:

6*4+ 1/2*4*4= 32 cm²

Answer:

30 years old

Step-by-step explanation:

Joe's age can be set to x. Since Billy is twice as old as Joe, his age can be set to 2x. They add up to 45. You can set up an equation, 2x+x=45.

Simplify the equation.

3x=45, x=15

Joe is 15. Billy is 2(15)=30.

Answer:

Read below.

Step-by-step explanation:

Questions are underlined

Answers are bolded

Which of the following statements is true?

If two polygons are similar then the corresponding sides are proportional and the corresponding angles are proportional.

If two polygons are similar, then the corresponding sides are proportional and  the corresponding angles are congruent.

If two polygons are similar, then the corresponding sides are congruent and the corresponding angles are proportional.

None of the choices are correct.

Which of the following sides are corresponding if ΔABC is similar to ΔMNL?

AC and ML, BC and NL, AB and MN is the correct answer but the answer choices are:

AB and MN, BC and NL, AC and ML

AC and MN, BC and NL, AB and ML

AB and ML, BC and NL, AC and MN

None of the choices are correct.

Answer:

Option (2).

Step-by-step explanation:

From the figure attached,

EFGH is a quadrilateral and FH is line which divides the quadrilateral into two right triangles, ΔFEH and ΔHGF.

In ΔFEH and ΔHGF,

Sides EH ≅ FG [Given]

FH ≅ FH [reflexive property]

ΔFEH ≅ ΔHGF [HL (Hypotenuse - length) postulate of congruence]

Option (2) will be the answer.

Answer:

4.700

Step-by-step explanation:

Find the number in the thousandth place  0  and look one place to the right for the rounding digit 4. Round up if this number is greater than or equal to 5 and round down if it is less than 5.

brainliesssss plssssssssssssss

Answer:

  C

Step-by-step explanation:

The function of table A can be written as ...

  y = 100x -92

__

The function of table B can be written as ...

  y = 10x +446

__

The function of table C can be written as ...

  y = (5/3)·3^x

__

The function of table D can be written as ...

  y = 2x +413

__

The exponential function of Table C will have the largest y-values for any value of x greater than 6.

_____

Comment on the functions

When trying to determine the nature of the function, it is often useful to look at the differences of the y-values for consecutive x-values. Here, the first-differences are constant for all tables except C. That means functions A, B, D are linear functions.

If the first differences are not constant, one can look at second differences and at ratios. For table C, we notice that each y-value is 3 times the previous one. That constant ratio means the function is exponential, hence will grow faster than any linear function.

Answer:

yes, what the other user  is correct i just took the quiz

Step-by-step explanation:

Answer:

A.

Step-by-step explanation:

So you would have f(3) = 3 + [tex]\frac{2}{2}[/tex]

f(3) = 3 + 1

f(3) = 4

Answer:

Step-by-step explanation: f(x)

3+ a square root of 3+1 / x-1

3+ a square root (4/2)

3+ square root of 2. That's the answer

Answer:

Radius = 13 m

Step-by-step explanation:

Formula for area of circle is given as:

[tex]A = \pi {r}^{2} \\ \\ \therefore \: 169\pi \: = \pi {r}^{2} \\ \\ \therefore \: {r}^{2} = \frac{169\pi }{\pi} \\ \\ \therefore \: {r}^{2} = 169 \\ \\ \therefore \: {r} = \pm \sqrt{169} \\ \\\therefore \: r = \pm \: 13 \: m \\ \\ \because \: radius \: of \: a \: circle \: can \: not \: be \: a \: negative \: \\quantity \\ \\ \huge \red{ \boxed{\therefore \: r = 13 \: m }}[/tex]

Answer:

D. $7.50

Step-by-step explanation:

$157.50 / 21 hours = $7.50 per hour

[tex]answer \\ 13.5 \: m/s \\ given \\ initial \: velocity(u) = \: 3 \: m/s \\ acceleration(a) = 1.5 \: m/s ^2\\ time(t) = 7 \: second \\ now \\ v = u + at \\ or \: v = 3 + 1.5 \times 7 \\ \: or \: v = 3 + 10.5 \\ v = 13.5 \: m/s \\ hope \: it \: helps[/tex]