The SAT is required of most students applying for college admission in the United States. This standardized test has gone through many revisions over the years. In 2005, a new writing section was introduced that includes a direct writing measure in the form of an essay. People argue that female students generally do worse on math tests but better on writing tests. Therefore, the new section may help reduce the usual male lead on the overall average SAT score (The Washington Post, August 30, 2006). Consider the following scores on the writing component of the test of eight male and eight female students.


Males Females
620 660
570 590
540 540
580 560
590 610
580 590
480 610
620 650
570 600
610 620
590 630
570 640
610 590
590 640
570 580
550 560
530 570
560 560
620 600
520 600
560 590
620 590
580 590
610 630
530 560
480 600
590 560
620 560
590 560
580 560

Required:
a. Construct the null and the alternative hypotheses to test if females outscore males on writing tests.
b. Assuming the difference in scores is normally distributed, calculate the value of the test statistic. Do not assume that the population variances are equal.
c. Implement the test at α=0.01 and interpret your results.

Answers

Answer 1

Answer:\

a

The null hypothesis is  [tex]H_o : \mu_1 - \mu_2 \le 0[/tex]

The alternative hypothesis is  [tex]H_a :  \mu_1 - \mu_2 > 0[/tex]

b

[tex]t  = -0.39[/tex]

c

The conclusion

There is sufficient evidence to conclude that the female outscores the male.

Step-by-step explanation:

From the question we are told that

  The  sample size for male  is  [tex]n_1  =  30[/tex]

    The sample size for female is  [tex]n_2  =  30[/tex]

 The level of significance is  [tex]\alpha = 0.01[/tex]

The null hypothesis is  [tex]H_o : \mu_1 - \mu_2 \le 0[/tex]

The alternative hypothesis is  [tex]H_a :  \mu_1 - \mu_2 > 0[/tex]

Generally the sample mean for male is  

     [tex]\= x_1  =  \frac{\sum x_i}{n_1}[/tex]

=>   [tex]\= x_1  =  \frac{620 + 570 +540 + \cdots + 580  }{30}[/tex]

=>   [tex]\= x_1  =  574.33 [/tex]  

Generally the standard deviation of  male is  

     [tex]s_1 = \sqrt{\frac{\sum (x_1 - \= x)^2}{n_1} }[/tex]

=>  [tex]s_1 = \sqrt{\frac{ (620 - 574.33)^2 + (570 - 574.33)^2 +  (540 - 574.33)^2 + \cdots +(580 - 574.33)^2  }{30} }[/tex]

=>  [tex]s_1 =206.24 [/tex]

Generally the sample mean for female is  

     [tex]\= x_2  =  \frac{\sum x_i}{n_2}[/tex]

=>   [tex]\= x_2  =  \frac{660 + 590 +560 + \cdots + 560  }{30}[/tex]

=>   [tex]\= x_2  =  593.33 [/tex]      

Generally the standard deviation of  male is  

 [tex]s_2 = \sqrt{\frac{\sum (x_1 - \= x)^2}{n_2} }[/tex]

=>  [tex]\sigma_1 = \sqrt{\frac{ (660 - 593.33)^2 + (590 - 593.33)^2 +  (560 - 593.33 )^2 + \cdots +(560 - 593.33)^2  }{30} }[/tex]

=>  [tex]s_2 =169.31 [/tex]

Generally the degree of freedom for unequal  variance is mathematically represented as  

[tex]df  =  \frac{[\frac{s_1^2}{n_1}  +\frac{s_2^2}{n_2}   ]^2}{ \frac{[\frac{s_1^2}{n_1}]^2}{n_1 -1}  +\frac{[\frac{s_2^2}{n_2}]^2}{n_2 -1}  }[/tex]

=> [tex]df  =  \frac{[\frac{206.24^2}{30}  +\frac{169.31^2}{30}   ]^2}{ \frac{\frac{206.24^2}{30}}{30 -1}  +\frac{\frac{169.31^2}{30}}{30 -1}  }[/tex]

=>[tex]df  = 56[/tex]

Generally the test statistics is mathematically represented as

  [tex]t  = \frac{\= x _1- \= x_2 }{\sqrt{\frac{s_1^2}{n_1}  + \frac{s_2^2}{n_2}} }[/tex]

=> [tex]t  = \frac{574.33- 593.33 }{\sqrt{\frac{206.24^2}{30}  + \frac{169.31^2}{30}} }[/tex]

=> [tex]t  = -0.39[/tex]

From the t distribution table the value of  [tex]P(t < -0.39)[/tex] at a degree of freedom of  [tex]df  = 56[/tex] is  

   [tex]P(t <  -0.39) = 0.3490080[/tex]

Hence the p-value  is   [tex]p-value =  0.3490080[/tex]

From the values obtained we see that the p-value  is  >[tex]\alpha[/tex]

Hence we fail to reject the null hypothesis.

The conclusion is  

  There is sufficient evidence to conclude that the female outscores the male

 


Related Questions

Solve 6x - 7y= 16 for y.

Answers

Answer:

y = 6/7x -16/7

Step-by-step explanation:

6x - 7y= 16

Subtract 6x from each side

6x-7y-6x = -6x+16

-7y = -6x+16

Divide by -7

-7y/-7 = -6x/-7 + 16/-7

y = 6/7x -16/7

6x - 7y = 16

Subtract 6x from both sides.

-7y = -6x + 16

Divide both sides by -7

y = 6/7x - 16/7

Plzz answers its easy points!!!! im just really dumb!!!!

Answers

Answer:

see below

Step-by-step explanation:

V = Bh where B is the area of the base and h is the height

Divide each side by h

V/h = Bh/h

V/h = B

36/6 = B

6 = B

The area of the base is 6 in^2

5 3/4 x 2 1/3 =? wut da answer?

Answers

The answer is 13 5/12 hope this helps

Which operation results in an expression equivalent to ? 23y^4 - 6y^3 + 35y^2 - 20y
A. Q - P

B. PQ

C. P - Q

D. P + Q

Answers

Answer:

D. P + Q

Explanation:

Given:

P = 8y⁴ + 6y³ + 8y

Q = (5y² - 4y)(3y² + 7)

Required:

Determine which operation will give an expression equivalent to 23y⁴ - 6y³ + 35y² - 20y.

SOLUTION:

Perform each operation given to see which of them gives an expression equivalent to 23y⁴ - 6y³ + 35y² - 20y.

Q - P:

P = 8y⁴ + 6y³ + 8y

Q = (5y² - 4y)(3y² + 7)

Q - P = (5y² - 4y)(3y² + 7) - (8y⁴ + 6y³ + 8y)

(5y²(3y² + 7) -4y(3y² + 7)) - (8y⁴ + 6y³ + 8y)

(15y⁴ + 35y² - 12y³ - 28y) - (8y⁴ + 6y³ + 8y)

Open parentheses

15y⁴ + 35y² - 12y³ - 28y - 8y⁴ - 6y³ - 8y

Collect like terms

15y⁴ - 8y⁴ - 12y³ - 6y³ + 35y² - 28y - 8y

7y⁴ - 18y³ + 35y² - 36y

Therefore, P - Q does not give us an expression equivalent to 23y⁴ - 6y³ + 35y² - 20y.

PQ:

P = 8y⁴ + 6y³ + 8y

Q = (5y² - 4y)(3y² + 7) = (15y⁴ + 35y² - 12y³ - 28y)

PQ = (8y⁴ + 6y³ + 8y)(15y⁴ + 35y² - 12y³ - 28y)

=(8y⁴(15y⁴ + 35y² - 12y³ - 28y) +6y³(8y⁴ + 6y³ + 8y)(15y⁴ + 35y² - 12y³ - 28y) +8y(8y⁴ + 6y³ + 8y)(15y⁴ + 35y² - 12y³ - 28y))

= 120y⁸ . . . . .

Note: You don't need to perform this operation further anymore. It would definitely not give us the equivalent expression we are looking for. The degree of the leading term (120y⁸) is way too greater than the degree of the leading term (23y⁴) of the equivalent expression we are looking for.

Thus, PQ cannot give us an expression equivalent to 23y⁴ - 6y³ + 35y² - 20y.

P - Q:

P = 8y⁴ + 6y³ + 8y

Q = (5y² - 4y)(3y² + 7) = (15y⁴ + 35y² - 12y³ - 28y)

P - Q = (8y⁴ + 6y³ + 8y) - (15y⁴ + 35y² - 12y³ - 28y)

Open parentheses

8y⁴ + 6y³ + 8y - 15y⁴ - 35y² + 12y³ + 28y

Collect like terms

8y⁴ - 15y⁴ + 6y³ + 12y³ - 35y² + 8y + 28y

-7y⁴ + 18y³ - 35y² + 36y

Therefore, P - Q cannot give us an expression equivalent to 23y⁴ - 6y³ + 35y² - 20y.

P + Q:

P = 8y⁴ + 6y³ + 8y

Q = (5y² - 4y)(3y² + 7) = (15y⁴ + 35y² - 12y³ - 28y)

P + Q = (8y⁴ + 6y³ + 8y) + (15y⁴ + 35y² - 12y³ - 28y)

Open parentheses

8y⁴ + 6y³ + 8y + 15y⁴ + 35y² - 12y³ - 28y

Collect like terms

8y⁴ + 15y⁴ + 6y³ - 12y³ + 35y² + 8y - 28y

23y³ - 6y³ + 35y² - 20y

Therefore, P + Q will result in an expression equivalent to 23y⁴ - 6y³ + 35y² - 20y.

The answer is D.

Ten less than a number is twice the same number​

Answers

Answer:Less ten a number; 20 - 10.10 ×2 = 20

Meaning lees 10 from 20 and multiply

Hi there!

First of all, let the unknown number be z.

Now, subtract 10:

z-10

This expression is equal to twice the same number:

z-10=2z

Solve this equation:

z-2z=10

-z=10

Divide both sides by -1 in order to get rid of the minus sign:

z=-10

Hope everything is clear.

Let me know if you have any questions!

#KeepLearning

:-)

instructions: analyze the diagram below and complete the instructions that follow​

Answers

Answer:

75°

Step-by-step explanation:

x+60=5x. (vertical angles)

4x=60

x=15

m<GJI = x+60

=15+60 = 75°

Find the area of the circle look no

Answers

Area of a complete circle is area = pi x r ^2

Area = 3.14 x 4^2

Area = 3.14 x 16

Area = 50.24 square units.

1/4 of the circle is missing, so multiply the area of the full circle by 3/4:

50.24 x 0.75 = 37.68 cubic units.

Find the equation of a parabola with a focus at (–2,–3) and a directrix at y = –5.

A)

y = 1∕4(x – 2)2 – 4

B)

y = –1∕16(x + 2)2 – 4

C)

y = 1∕4(x + 2)2 – 8

D)

y = 1∕4(x + 2)2 – 4

Answers

C if i’m not mistaken

Answer:

It"s (C) byeeee and ur welcome

Find the slope of f(x)=5x-4

Answers

Answer:

5

Step-by-step explanation:

Answer:

slope, m = 5

Step-by-step explanation:

Recall that the slope-intercept form of a linear equation can be written:

y = mx + b  or f(x) = mx + b

where m is the slope of the line.

in our case, we are given

f(x) = 5x - 4

if we compare this with the general equations above, we can see that

slope = m = 5

hence the slope is 5

A machine in a factory produces 25 gismos a day. After a $174 repair job, the machine improves its gizmo output by 16%.If the sale of a gizmo makes a profit of 75cents, the number of days it will take to recover the machine's repair is???




PLEAS HELP ME!!!

Answers

Answer:

Around 10 days ( 9.28 days: 9 days 6 hours 43 minutes 12 seconds).

Step-by-step explanation:

Given that 25 gizmos are produced each day, and 75 ¢ are made off of each one, a 174$ repair job will take away money that will need to be paid off.

We can create the following equation by using the amount of gizmos earned per day(x or time) multiplied the money made off of each one(in cents ¢), is equal to the repair job since it will be paid off once it is canceled out.

25x(75¢) = 174$.

Since the money made by each gizmo is in cents and not dollars, it is best to convert this into dollars since the repair job is in this form. Because 100¢ are in each dollar, 75¢ = 75/100 dollars = 3/4 dollars.

3/4 * 25 x = (3/4) * (25x) = (25*3) / 4 = 75/4x

(75/4)x = 174$

(75/4x) * (4/75) = (174$) * (4/75)

x = (174 * 4) / 75

x = 696 / 75

x = 9.28

We are multiplying by the reciprocal (numerator and denominator are switched) since it will make your coefficient 1 which is the variable itself. anything times it's reciprocal is equal to one.

75/4x = 174$

×4 ×4

(cancel out the denominator)

____________

75x = 696$

÷ 75 ÷ 75

(cancel out 75 to get the variable by itself)

___________

x = 696/75

x = 232/25

x = 928/100

x = 9.28

___________

Using a system of equation, the number of days it will take to recuvwr the repair cost is 58 days.

The increase in amount of gizmo produced after repair :

0.16) × 25 = 4 gizmos per day

Prize per gizmo = 75 cent = $0.75

Repair cost = $174

The number of days it will take to recover the repair fee can be calculated thus :

(Increase on gizmo per day × cost per gizmo)× number of days = repair fee

(4 × 0.75)d= 174

3d = 174

d = 174 / 3

d = 58

Therefore, it will take 58 days to recover the repair fee.

Learn more : https://brainly.com/question/18796573

PLEASE HELP ASAP!!
There are 800 students who attend Park Middle School. There are 1.5 times as many boys as there are girls.
x is boys
y is girls
800=1.5x=y
Determine how many boys and girls attend Park Middle School. Round to the nearest whole number if necessary. Show your work.

Answers

Answer:

320 boys; 480 girls

Step-by-step explanation:

Here is the correct system of equations you can write for this equation:

1.5x=y

x+y=800

x+1.5x=800

2.5x=800

x=320

320+y=800

y=480

Note: Enter your answer and show all the steps that you use to solve this problem in the space provided.
a) Simplify the expression and explain each step. (2 points)
4(3x+2)−2
b) Factor the expression completely. (1 point)
20b−16

Answers

bbaxjs ,hjghlgthjgthjnrgtirtmjogrthinlgtrknhgtrhgtlkjbvgthjbmhjvtg

Where is the point (-8,0) located on the coordinate plane?

1. On the X-axis
2. In quadrant ll
3. In quadrant lll
4. On the y-axis​

Answers

on the x-axis but i’m not 100% sure

Help pls it’s urgent

Answers

Answer:

d. -2

Step-by-step explanation:

they're telling you those lines are parallel there are specific knowns about the angles

since it's urgent I won't go into it, but PLS look it up it's super simple and makes sense

nonetheless this means angle 1 and angle 5 are the same value so we can set them equal

3x + 24 = 7x + 32

substract 32 from both sides

3x - 8 = 7x

substract 3x from both sides

-8 = 4x

divide 4 from both sides

-2 = x

-1/2(6t+2)?simplify the expressions by disturbing the negatives and combining like terms ​

Answers

Answer:

-3t-1

Step-by-step explanation:

AMY HAS TWO TOMATO PLANTS. ONE IS 5 3/4 INCHES TALL AND THE OTHER IS 8 1/2 INCHES TALL. WHAT IS THE DIFFERENCE IN HEIGHT BETWEEN THE TWO TOMATO PLANTS?

Answers

The answer is 2 3/4 inches


Kenya went to the convenience store to buy some candy bars for her friends. She spent a total of $6.00 on candy bars. Each candy bar cost $1.50.
How many candy bars did Kenya buy?

Answers

Answer:

4

Step-by-step explanation:

Answer:

4

Step-by-step explanation:

I need help with this question

Answers

Answer:

b

Step-by-step explanation:

Planes S and R both intersect plane T Which statements are true based on the diagram? Select three options OPlane S contains points B and E. The line containing points A and B lies entirely in plane T B ULine v intersects lines x and y at the same point ULine z intersects plane S at point C OPlanes R and T intersections at line y.​

Answers

Answer:

Options (2), (4) and (5)

Step-by-step explanation:

Option (1).

Planes S contains points B and F.

False.

(Point B lies on plane S and point F lies on plane R)

Option (2).

The line containing points A and B lie on the plane T.

True.

(points A and B lie on plane T)

Option (3).

Line v intersects lines x and y at the same plane.

False.

Option (4).

Line z intersects plane S at point C.

True.

Option (5).

Planes R and T intersect at line y.

True.

Answer:its b d e

Step-by-step explanation:

Find the equation of a line parallel to -5x+y=2 that contains the point (5,-2)

Answers

Step-by-step explanation:

y= 5x+2

Well first, parallel equations will always have to same slope so we know one part of the equation, 5x

I always plug in random numbers for b into desmos until the line passes through the given point orrrr you can use the point, plug it into the equation, and solve for b

-2=5(5)+b

Solve 2y - 3 = 4y +6.
у
DONE

Answers

Answer:

y= -4.5

Step-by-step explanation:

2y - 3 = 4y +6

subtract 2y from both sides: -3 = 2y +6

subtract 6 from both sides: -9 = 2y

divide both sides by 2: -4.5 = y

Answer:

y= -4.5

Step-by-step explanation:

2y - 3 = 4y + 6

+3 + 3

2y = 4y + 9

-4y -4y

-2y = 9

divide by -2 to get -4.5

Please help me with all the answers please say like 1: the answer 2: the answer like that thank you so much

Answers

1: 8200,82000,820000 yen
2:12
3:8
4:6
5:4 months

Plzzz help D.
A
Identify the nonlinear graph,
A)
А
B)
B
C)
D

Answers

it’s b if i’m not mistaken

Answer:

C.

Step-by-step explanation:

It is not a straight line therefore it cannot be linear.

What is the value of x?

Answers

Answer:

Step-by-step explanation:

where are the other variables?

Please answer this correctly without making mistakes

Answers

Answer:

the answser is 8%.

8% of the shape is blue

Which two numbers have a product of −18 and a sum of −7?

Answers

Answer:

2 and -9

Step-by-step explanation:

2 times -9 is -18

2 plus -9 is -7

Hope this helped!

find the value of x

need to show work

Thank you guys

Answers

Answer:

Since they are vertical angles (or angles opposite each other), you set them equal to each other.

5x + 4 = 74

5x = 70

x = 15

A scuba diver is 12 meters below sea level. If the diver descends 39 meters further, what integer represents the scuba diver’s new elevation relative to sea level?

Answers

I think the answer is -51

Find the value of X.

Answers

Answer:

x = 59

Step-by-step explanation:

34 + x - 30 + 5x + 2 = 360

34 - 30 + 2 + x + 5x = 360

4 + 2 + 6x = 360

6 + 6x = 360

6x = 354

x = 59

Hope this helped!

z=b+ m/a, solve for a

Answers

You can not solve for a as all of the numbers are unknown
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