Giving a test to a group of students, the grades and gender are summarized below

A B C Total
Male 7 20 14 41
Female 3 4 19 26
Total 10 24 33 67


If one student is chosen at random,

Find the probability that the student was male OR got an "A".

Answer:

I think that angles 1 and 2 are complementary

Step-by-step explanation:

option 1

plz mark brainliest!

Answer:a

Step-by-step explanation:

Answer: C

Step-by-step explanation:

To get all the constant terms on one side and variable terms on another, all we have to do is to add or subtract them on both sides.

3x+2x=10+5

Now that the like terms are on one side, we can combine them.

5x=15

To get x alone, we divide both sides by 5.

x=3

Now, we notice that x=3 is not an answer choice, but the next option that is equivalent to x=3 is C.

For C, if you divide both sides by -5, you still get x=3.

-15=-5x

x=3

4books=6.28inches

30books=?

(30x6.28)/4

47.1 inches

47.1 inches

Answer:

  2 + h = 14 and k - 25 = 2

Step-by-step explanation:

An equation has an equal sign.

Apparently, your answer choices are of the form ...

  (math expression) and (math expression)

In order for this to be "only equations", each "math expression" must contain an equal sign. That is, you must have ...

  ( ... = ... ) and ( ... = ... )

Something like ...

  c -14  and  d +134

contains no equal signs, so has no equations.

It looks like your appropriate choice is ...

  2 + h = 14 and k - 25 = 2

Answer:

the answer is a

Step-by-step explanation:

i took the test

:)

note: have a wonderful day!

Answer:

C: Multiply the first equation by -2

Step-by-step explanation:

-2 * (x + 3y = 16) = -2x-6y=-32

The resulting equation would be -2x-6y=-32

In the next if you add the two equations, you will successfuly eliminate x and can now solve for y.

-2x-6y=-32

2x + y = -18

Answer:

c

Step-by-step explanation:

x+3y=16________________eqn 1

2x+y=-18_______________eqn 2

multiply first equation by - 2

-2(x+3y=16)

-2x-6y= -32______________eqn 3

using elimination method

-2x-6y= -32

+

2x+y= -18

0-5y= -50

-5y= -50

divide both sides by -5

-5y/5= -50/5

y=10

substitute y in eqn 2 to find the value of x

2x+y= -18

2x+(10)= -18

2x+10= -18

2x= -18-10

2x= -28

divide both sides by 2

2x/2= -28/2

x= -14

Answer:

The degrees of freedom first given by:  

[tex]df=n-1=12-1=11[/tex]  

Then we can find the critical value taking in count the degrees of freedom and the alternative hypothesis and then we need to find a critical value who accumulates 0.05 of the area in the right tail and we got:

[tex] t_{\alpha}= 1.796[/tex]

And for this case the rejection region would be:

b) Reject H0 if tcalc >1.7960

Step-by-step explanation:

Information given

5, 7, 4, 6, 7, 5, 5, 6, 4, 4, 7, 5.

System of hypothesis

We want to test if the true mean is higher than 5, the system of hypothesis are :  

Null hypothesis:[tex]\mu \leq 5[/tex]  

Alternative hypothesis:[tex]\mu > 5[/tex]  

The statistic is given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)  

The degrees of freedom first given by:  

[tex]df=n-1=12-1=11[/tex]  

Then we can find the critical value taking in count the degrees of freedom and the alternative hypothesis and then we need to find a critical value who accumulates 0.05 of the area in the right tail and we got:

[tex] t_{\alpha}= 1.796[/tex]

And for this case the rejection region would be:

b) Reject H0 if tcalc >1.7960

Answer: THE SECOND ONE

Step-by-step explanation:

Answer: the second one

Step-by-step explanation:

Answer:24600 , 16400

Step-by-step explanation:

Let the first part be x

So, second part will be 41000 - x

For amount x

SI = prt / 100

SI = x * 0.50 * 2

SI = 1x

For amount 41000 - x

SI = (41000-x) * 0.50 * 3

SI = 61500 - 1.5x

1x = 61500 - 1.5x

1.5x + x = 61500

2.5x = 61500

x = 61500 / 2.50 = 24600 for 2 years

2nd part = 41000 - 24600 = 16400 for three years

Answer:-2

Step-by-step explanation:

Ok so I’m assuming the x stands for the multiplication sign

7/2-4.5*3+8

Use pemdas

Multiplication first

7/2-4.5*3+8

-4.5*3

7/2-13.5+8

Then addition

-13.5+8

Lastly subtraction

7/2-5

-2

Answer:

4.76% probability that a randomly selected person from the population has a positive test result

Step-by-step explanation:

We have these following probabilities:

4% probability of having the disease.

If a person has a disease, 95% probability of a positive test.

100-4 = 96% probability a person does not have the disease.

If a person does not have the disease, 1% probability of a positive test.

What is the probability that a randomly selected person from the population has a positive test result

95% of 4% and 1% of 96%. So

p = 0.95*0.04 + 0.01*0.96 = 0.0476

4.76% probability that a randomly selected person from the population has a positive test result

Answer:

615.44

Step-by-step explanation:

The area in terms of π is 196π

196 * 3.14 = 615.44

Answer:

615.75

Step-by-step explanation:

Area equals pi times r times 2

A equals 3.14 times 14 times 2

Answer and Step-by-step explanation:

The computation of annual and quarterly mortality rates per 100,000 population is shown below:-

Quarterly mortality rates are

[tex]= \frac{Deaths}{Population\ in\ the\ city}\times Population[/tex]

For the first quarter

[tex]= \frac{54}{450,000}\times 100,000[/tex]

= 12  death per 100,000 population

For the second quarter

[tex]= \frac{43}{450,000}\times 100,000[/tex]

= 9.5  death per 100,000 population

For the third quarter

[tex]= \frac{35}{450,000}\times 100,000[/tex]

= 7.7  death per 100,000 population

For the fourth quarter

[tex]= \frac{39}{450,000}\times 100,000[/tex]

= 8.6  death per 100,000 population

Now the annual mortality is

[tex]= \frac{Deaths}{Population\ in\ the\ city}\times Population[/tex]

[tex]= \frac{171}{450,000}\times 100,000[/tex]

= 38 death per 100,000 population

Answer:

The value of x^3 + 1/x^3 is 47/x + 1/x^3 - 1/x^5

Step-by-step explanation:

x^4 + 1/x^4 = 47

x^4 = 47 - 1/x^4

x^3 + 1/x^3 = 1/x(x^4 + 1/x^2)

x^4 = 47 - 1/x^4

x^3 + 1/x^3 = 1/x(47 - 1/x^4 + 1/x^2) = 47/x - 1/x^5 + 1/x^3 = 47/x + 1/x^3 - 1/x^5

Answer:

x = 15

Step-by-step explanation:

3x = 45

x = 45/3

x = 15

Answer:

15

Step-by-step explanation:

3x = 45

Dividing 3 from both sides gives you

[tex]x = 45/3\\\\[/tex]

Now that isolated x.

[tex]45/3 = 15[/tex]

So x = 15

:D

Answer:

The proportion of the variability seen in math achievement that can be predicted by math attitude is 0.78, the same value as the correlation coefficient.

Step-by-step explanation:

The correlation coefficient r between this two variables is found to be 0.78.

This coefficient can be calculated as:

[tex]r=\dfrac{SSY'}{SSY}[/tex]

where SSY' is the sum of the squares deviation from the mean for the predicted value and SSY is the sum of the squares deviation from the mean for the criterion variable.

Then, the value of the coefficient r is giving the proportion of the variability seen in the criterion value Y that can be explained by the predictor variable X.

Answer:

r=SSY'/SSY

Step-by-step explanation:

Answer:

subtract  -3

Step-by-step explanation:

–3 + 4x = 9

Add 3 to each side

This is the same as subtracting -3

-3 + 4x - (-3) = 9 - (-3)

4x = 9 +3

4x = 12

Answer:

C.

Step-by-step explanation:

Central angle = 360-52=308°

In radians

308° = 308π/180

Now

S = r∅

S = 3×308π/180

S = 924π /180

S = 77π/15 in.

Answer:

answer is 13π/15

Step-by-step explanation:

correct answer is 13π/15.

Answer:

She drove 8 miles each day.

Step-by-step explanation:

Given that she drove equal number of miles in 5 days. So in order to find the number of miles in each days, you have to divide it by 5,

[tex]5days = 40miles[/tex]

[tex]1day = 40 \div 5[/tex]

[tex]1day = 8miles[/tex]

Answer:

The original price of the fan is $35.71

Step-by-step explanation:

Since Griffin’s General Store is having a 30% off sale on fans, it simply means that fans are paying for (100%-30%)= 70%.

Let the original price be x;

Therefore, 70% of x equal to $25;

[tex]\frac{70}{100}x=25[/tex]

70/100x = 25

0.7x = 25

[tex]x = \frac{25}{0.7}[/tex]

x = 35. 71

Hence, The original price of the fan is $35.71

Answer:

$35.71

Step-by-step explanation:

The statement indicates that Robert paid $25 for a fan and that it had a 30% discount. To be able to determine the original price, you have to divide the the price with the discount by the result of 1 minus the discount.

Original price= 25/(1-0.3)

Original price= 25/0.7

Original price= 35.71

According to this, the answer is that the original price of the fan is $35.71.

Hey there! I'm happy to help!

We want to find out how much Lana pays per month. Let's dissect each payment we are given so we can find our monthly expense.

---------------------------------------------------------------------------

AUTOMOBILE INSURANCE

$300 for automobile insurance semiannually

The prefix semi- means half. Annual means year. So, she is paying $300 every half year, or six months. So, we can divide 300 by 6 to find how much she pays in one month!

300/6=50

Therefore, she pays $50 a month for automobile insurance.

---------------------------------------------------------------------------

HEALTH INSURANCE

We are told here that she pays $100 every month for health insurance. We don't need do anything else here!

---------------------------------------------------------------------------

LIFE INSURANCE

We see that Lana pays $700 per year on life insurance. We can divide this by 12 to find out how much there is in 1 month!

700/12≈58.33

Therefore, she pays $58.33 every month on life insurance.

---------------------------------------------------------------------------

SOLUTION

Now, we just add all of these monthly totals up to find Lana's monthly expense.

50+100+58.33=208.33

Therefore, Lana's monthly expense is $208.33.

I hope that this helps! Have a wonderful day!

Answer:

[tex]E_{A} =0.25*160=40[/tex]  

[tex]E_{B} =0.25*160=40[/tex]

[tex]E_{C} =0.4*160=64[/tex]

[tex]E_{D} =0.05*160=8[/tex]  

[tex]E_{F} =0.05*160=8[/tex]  

And now we can calculate the statistic:  

[tex]\chi^2 = \frac{(36-40)^2}{40}+\frac{(42-40)^2}{40}+\frac{(60-64)^2}{64}+\frac{(14-8)^2}{8}+\frac{(8-8)^2}{8} =5.25[/tex]  

The answer would be:

c. 5.25

Step-by-step explanation:

The observed values are given by:

A: 36

B: 42

C: 60

D: 14

E: 8

Total =160

We need to conduct a chi square test in order to check the following hypothesis:  

H0: There is no difference in the proportions for the final grades

H1: There is a difference in the proportions for the final grades

The level of significance assumed for this case is [tex]\alpha=0.01[/tex]  

The statistic to check the hypothesis is given by:  

[tex]\chi^2 =\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}[/tex]  

Now we just need to calculate the expected values with the following formula [tex]E_i = \% * total[/tex]  

And the calculations are given by:  

[tex]E_{A} =0.25*160=40[/tex]  

[tex]E_{B} =0.25*160=40[/tex]

[tex]E_{C} =0.4*160=64[/tex]

[tex]E_{D} =0.05*160=8[/tex]  

[tex]E_{F} =0.05*160=8[/tex]  

And now we can calculate the statistic:  

[tex]\chi^2 = \frac{(36-40)^2}{40}+\frac{(42-40)^2}{40}+\frac{(60-64)^2}{64}+\frac{(14-8)^2}{8}+\frac{(8-8)^2}{8} =5.25[/tex]  

The answer would be:

c. 5.25

Now we can calculate the degrees of freedom for the statistic given by:  

[tex]df=(categories-1)=(5-1)=4[/tex]

And we can calculate the p value given by:  

[tex]p_v = P(\chi^2_{4} >5.25)=0.263[/tex]  

The p value is higher than the significance so we have enough evidence to FAIL to reject the null hypothesis

Answer:

Step-by-step explanation:

We have to find the reported happiness of person of family income of $25,000, $35,000 and $45,000

Given that the formula for finding relation between a people happiness and his income is

y = 0.065x - 0.613

a) find the happiness of person of family income os $25,000

we put x = 25 as in the equation above

[tex]y=0.065(25)-0.613\\\\=1.625-0.613\\\\=1.02 \approx 1[/tex]

Hence, person happiness with with family income of $25,000 on a scale of 3 is y = 1

That means they come under catergory "not to happy"

b) Find the happiness of person of family income os $35,000

we put x = 35 as in the equation above

[tex]y=0.065(35)-0.613\\\\=1.667-0.613\\\\=1.667 \approx 1.7[/tex]

Hence, person happiness with with family income of $35,000 on a scale of 3 is y = 1.7

That means they come under catergory "not to happy" and "fairly happy"

c) Find the happiness of person of family income os $45,000

we put x = 45 as in the equation above

[tex]y=0.065(45)-0.613\\\\=2.925-0.613\\\\=2.312 \approx 2.3[/tex]

Hence, person happiness with with family income of $45,000 on a scale of 3 is y = 2.3

That means they come under catergory  "fairly happy"

The scale would show the data as follows:

Happiness Scale at Income 25, 35, 45 & 55 thousand :

1.012 (Not too happy), 1.662 (Fairly Happy), 2.315 (Fairly Happy) , 2.965 (Very Happy)

Important Information :

Relationship between happiness scale 'y' and income in 1000s 'x' :y = 0.065x − 0.613, for people in income group between [tex]25000 & 55000[/tex]

Happiness scale : At level of income, between 25 and 55 thousands.

Putting value of income 'x' to find scale of happiness i.e. 'y'

For income 'x' = 25 thousand : [tex]y = 0.065 (25) - 0.613 = 1.625 - 0.613 = 1.012[/tex] For income 'x' = 35 thousand : [tex]y = 0.065 (35) - 0.613 = 2.275 - 0.613 = 1.662[/tex]For income 'x' = 45 thousand : [tex]y = 0.065 (45) - 0.613 = 2.925 - 0.61 = 2.315[/tex] For income 'x' = 55 thousand :[tex]y = 0.065 (55) - 0.613 = 3.575 - 0.61 = 2.965[/tex]

Learn more about "Happiness Scale" here:

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Answer:

For ease of writing, θ [tex]=x[/tex]

[tex]sin(x)=\frac{1}{\sqrt{2} }[/tex]

[tex]cos(x)=-\frac{1}{\sqrt{2} }[/tex]

Step-by-step explanation:

Our angle is [tex]x=\frac{3\pi }{4}[/tex]

To find our answers for [tex]sin(\frac{3\pi}{4} )[/tex] and [tex]cos(\frac{3\pi}{4} )[/tex], we will need to use a unit circle. (I have attached the image of one).

Recall that the [tex]sin[/tex] of an angle is equal to the y-value of the corresponding ordered pair.

And the [tex]cos[/tex] of an angle is equal to the x-value of the corresponding ordered pair.

For the angle [tex]x=\frac{3\pi }{4}[/tex], the ordered pair is [tex](-\frac{1}{\sqrt{2}} }, \frac{1}{\sqrt{2} } )[/tex]

This means that

[tex]sin(x)=\frac{1}{\sqrt{2} }[/tex]

[tex]cos(x)=-\frac{1}{\sqrt{2} }[/tex]

Answer:

[tex] x =\frac{-b \pm \sqrt{b^2 -4ac}}{2a}[/tex]

Where a = 2 , b= 3, c= -5, replacing we have this:

[tex]x =\frac{-3 \pm \sqrt{(-3)^2 -4(2)(-5)}}{2*2}[/tex]

And simplifying we got:

[tex] x = \frac{-3 \pm \sqrt{49}}{4}[/tex]

And the two solutions are:

[tex] x_1 = \frac{-3+7}{4}= 1[/tex]

[tex] x_2 = \frac{-3-7}{4}= -\frac{5}{2}[/tex]

And the correct options are:

B and C

Step-by-step explanation:

We have the following equation given:

[tex] 2x^2 +3x -5=0[/tex]

And if we use the quadratic formula given by:

[tex] x =\frac{-b \pm \sqrt{b^2 -4ac}}{2a}[/tex]

Where a = 2 , b= 3, c= -5, replacing we have this:

[tex]x =\frac{-3 \pm \sqrt{(-3)^2 -4(2)(-5)}}{2*2}[/tex]

And simplifying we got:

[tex] x = \frac{-3 \pm \sqrt{49}}{4}[/tex]

And the two solutions are:

[tex] x_1 = \frac{-3+7}{4}= 1[/tex]

[tex] x_2 = \frac{-3-7}{4}= -\frac{5}{2}[/tex]

And the correct options are:

B and C

Answer:

B and C

Step-by-step explanation:

Answer:

solution is [tex]\boxed{x=-1,x=-11}[/tex]

Step-by-step explanation:

f(x)=2|x+6|-4

either x+6 is positive and then |x+6|=x+6

or it is negative and |x+6| = -(x+6)=-x-6

case 1: x>=-6

f(x)= 2x+12-4=2x+8

f(x)=6 <=> 2x+8=6 <=> 2x = 6-8=-2 <=> x = -1

case 2: x<=-6

f(x)=-2x-12-4=-2x-16

f(x)=6 <=> -2x-16=6 <=> 2x=-16-6 = -22 <=> x = -11

so to recap, the solutions are x=-1 and x=-11

The value of x from the modulus value function is x = -1 and x = -11

Regardless of the sign, a modulus function returns the magnitude of a number. The absolute value function is another name for it.

It always gives a non-negative value of any number or variable. Modulus function is denoted as y = |x| or f(x) = |x|, where f: R → (0,∞) and x ∈ R.

The value of the modulus function is always non-negative. If f(x) is a modulus function , then we have:

If x is positive, then f(x) = x

If x = 0, then f(x) = 0

If x < 0, then f(x) = -x

Given data ,

Let the function be represented as A

Now , the value of A is

f ( x ) = 2 | x + 6 | - 4   be equation (1)

On simplifying , we get

when the value of f ( x ) = 6

Substituting the value of f ( x ) = 6 , we get

6 = 2 | x + 6 | - 4  

Adding 4 on both sides , we get

2 | x + 6 | = 10

Divide by 2 on both sides , we get

| x + 6 | = 5

And , If x is positive, then f(x) = x

If x = 0, then f(x) = 0

If x < 0, then f(x) = -x

So , the two values of x are given by

when x + 6 = -5 and x + 6 = 5

x = -1 and x = -11

Hence , the values of x of modulus function is x = -1 and x = -11

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Answer: It’s 2

Step-by-step explanation:

look at picture

Answer:

The probability of selecting two red balls is 0.132.

Step-by-step explanation:

In a bag there are 10 balls in a bag, 4 red balls and 6 black balls.

The conditions of selecting a ball are:

It is also provided that only one ball can be picked at a time.

Now, it is given that two balls are picked.

The number of ways to select a red ball in the first draw is: [tex]{4\choose 1}=4\ \text{ways}[/tex]

Compute the probability of selecting a red ball in the first draw as follows:

[tex]P(\text{First ball is Red})=\frac{{4\choose 1}}{{10\choose 1}}=\frac{4}{10}=0.40[/tex]

Now as a red ball is selected it will not be replaced.

So, there are 9 balls in the bag now.

The number of ways to select a red ball in the second draw is: [tex]{3\choose 1}=3\ \text{ways}[/tex]

Compute the probability of selecting a red ball in the second draw as follows:

[tex]P(\text{Second ball is Red})=\frac{{3\choose 1}}{{9\choose 1}}=\frac{3}{9}=0.33[/tex]

Compute the probability of selecting two red balls as follows:

[tex]P(\text{Two Red balls})=P(\text{First ball is Red})\times P(\text{Second ball is Red})[/tex]

                            [tex]=0.40\times 0.33\\\\=0.132[/tex]

Thus, the probability of selecting two red balls is 0.132.

Answer:  The answer has one solution:

_______________________________

      →  x = 1 ;   y =  -4 ;  or, write as:  [1, -4].

_______________________________

Step-by-step explanation:

_______________________________

Given:

  y  =  - 1x – 3

  y  =   -7x + 3 ;

_______________________________

    -1x – 3  =   -7x + 3  ;  Solve for "x" ;

Add:  " +1x" ; and add " +3 " ;  to Each Side of the equation:

Subtract " 1x " ; and Subtract " 1 " ; from Each Side of the equation:

   -1x  + 1x  – 3  + 3  =  -7x  + 1x + 3 + 3 ;

         to get:  

             0  =  -6x + 6

          ↔  -6x + 6 = 0 ;

Now, subtract " 6 " from Each Side of the equation:

                -6x + 6 – 6  = 0 – 6  ;

       to get:

               -6x = -6 ;

Now, divide Each Side of the equation by " -6 ";  

      to isolate "x" on one side of the equation;

      & to solve for "x" ;

              -6x /-6  =  -6/-6 ;

      to get:

                x = 1 .

_______________________________

Now, let us solve for "y" ;  

We are given:  

 y =  -x – 3  ;

Substitute our solved value for "x" ; which is:  " 1 " ; for " x " ; into this given equation; to obtain the value for " y " :

 y =  -x – 3  ;

    =  -1  – 3  

 y =   - 4 .

_______________________________

Let us check our answers by plugging the values for "x" and "y" ;

" 1 " ; and " -4 "; respectively);  into the second given equation; to see if these values for " x " and " y"  ; hold true:

Given:   y  =    - 7x  +  3 ;

           →  -4   =?  -7(1) + 3 ??  ;

           →  -4   =?   -7   + 3  ??  ;

           →  - 4 =?   -4 ?? ;

           →  Yes!

_______________________________

The answer has one solution:

      →  x = 1 ;   y =  - 4 ;  or, write as:  [1, -4 ].

_______________________________

Hope this is helpful!  Best wishes!

_______________________________

Answer:

a) Binomial.

b) n=20, p=0.01, k≥2

The probability hat a package sold will be refunded is P=0.0169.

Step-by-step explanation:

a) We know that

The most appropiate distribution to represent this random variable is the binomial.

b) The parameters are:

The probability of the package being refunded can be calculated as:

[tex]P(x\geq2)=1-(P(x=0)+P(x=1))\\\\\\P(x=k) = \dbinom{n}{k} p^{k}q^{n-k}\\\\\\P(x=0) = \dbinom{20}{0} p^{0}q^{20}=1*1*0.8179=0.8179\\\\\\P(x=1) = \dbinom{20}{1} p^{1}q^{19}=20*0.01*0.8262=0.1652\\\\\\P(x\geq2)=1-(0.8179+0.1652)=1-0.9831=0.0169[/tex]

Answer:

  AB = 2√106 ≈ 20.591

Step-by-step explanation:

The Pythagorean theorem says the square of the hypotenuse is equal to the sum of the squares of the legs.

For median AM, we have ...

  AM² = CM² +AC² = (BC/2)² +AC²

For median BN, we have ...

  BN² = CN² +BC² = (AC/2)² +BC²

The sum of these two equations is ...

  AM² +BN² = BC²/4 +AC² +AC²/4 +BC² = (5/4)(AC² +BC²)

  AM² +BN² = (5/4)(AB²)

The hypotenuse of triangle ABC is then ...

  AB = √(4/5(AM² +BN²))

  AB = 2√((19² +13²)/5)

  AB = 2√106 ≈ 20.591