A certain test preparation course is designed to help students improve their scores on the MCAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 7 students' scores on the exam after completing the course: 37,12,12,17,13,32,23 Using these data, construct a 80% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. Step 1 of 4 : Calculate the sample mean for the given sample data. Round your answer to one decimal place.

Answers

Answer 1

Answer:

The 80% confidence interval for the average net change in a student's score after completing the course is (15.4, 26.3).

Step-by-step explanation:

The net change in 7 students' scores on the exam after completing the course are:

S = {37 ,12 ,12 ,17 ,13 ,32 ,23}

Compute the sample mean and sample standard deviation as follows:

[tex]\bar x=\frac{1}{n}\sum x=\frac{1}{7}\times 146=20.857\\\\s=\sqrt{\frac{1}{n-1}\sum (x-\bar x)^{2}}}=\sqrt{\frac{1}{7}\times 622.8571}=10.189[/tex]

As the population standard deviation is not known, a t-interval will be formed.

Compute the critical value of t for 80% confidence interval and 6 degrees of freedom as follows:

[tex]t_{\alpha/2, (n-1)}=t_{0.20/2, (7-1)}=t_{0.10,6}=1.415[/tex]

*Use a t-table.

Compute the 80% confidence interval for the average net change in a student's score after completing the course as follows:

[tex]CI=\bar x\pm t_{\alpha/2, (n-1)}\times\frac{s}{\sqrt{n}}[/tex]

     [tex]=20.857\pm 1.415\times\frac{10.189}{\sqrt{7}}\\\\ =20.857\pm 5.4493\\\\=(15.4077, 26.3063)\\\\\approx (15.4,26.3)[/tex]

Thus, the 80% confidence interval for the average net change in a student's score after completing the course is (15.4, 26.3).


Related Questions

5 yüz binlik 2 binlik 4 yüzlükten oluşan
altı basamaklı doğal sayı kaçtır?

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Answer:

wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww

Solve the inequality: -2x>-6

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Answer:

x < 3

Step-by-step explanation:

Divide both sides by -2

x < -6/-2

Two negatives equals a positive

x < 6/2

Simplify 6/2 to 3

x < 3

Hope this helps!

-Jerc

Solve for x in the triangle. Round your answer to the nearest tenth.

Answers

Answer: x ~34.31 (rounded)

Graph the image of the given triangle after the transformation that has the rule (x, y)→(x−5, y+6). Select the Polygon tool. Then, click the points of the triangle vertices to create the triangle by connecting the sides.

Answers

Answer:

Step-by-step explanation:

Transformation involves changing the position of a shape in the coordinate.

See attachment for the image of the triangle

Assume the triangle is triangle ABC.

The coordinates of ABC are:

[tex]\mathbf{A = (-1,-4)}[/tex]

[tex]\mathbf{B = (-2,-7)}[/tex]

[tex]\mathbf{C = (5,-6)}[/tex]

The transformation rule is given as:

[tex]\mathbf{(x,y) \to (x -5,y+6)}[/tex]

So, we have:

[tex]\mathbf{A' = (-1 -5,-4+6)}[/tex]

[tex]\mathbf{A' = (-6,2)}[/tex]

[tex]\mathbf{B' = (-2 -5,-7+6)}[/tex]

[tex]\mathbf{B' = (-7,-1)}[/tex]

[tex]\mathbf{C' = (5 -5,-6+6)}[/tex]

[tex]\mathbf{C' = (0,0)}[/tex]

So, the coordinates of the new triangle would be:

[tex]\mathbf{A' = (-6,2)}[/tex]

[tex]\mathbf{B' = (-7,-1)}[/tex]

[tex]\mathbf{C' = (0,0)}[/tex]

See attachment for the image of ABC

Read more about transformations at:

https://brainly.com/question/12463306

The value of a stock over a 12 year period form 2003 to 2015 is shown in the line graph. Which statement is not supported by the graph?

Answers

The correct answer is the last one listed: the statement not supported by the graph is that a stock purchased in 2006 has not yet recovered the losses from 2008. That is not true.

Answer:

an individual who invested in the market in 2006  has yet to regain the losses incurred in 2008

Step-by-step explanation:

Enter the sum of numbers as a product of their GCF.
30 + 36
The sum of the numbers as a product of their GCF is

Answers

Their GCF is 6 and the sum is 66

Step-by-step explanation:

Gabrielle’s age is two times Mikhail’s age. The sum of their ages is 36. What is Mikhail’s age?

Answers

Mikhail’s age is 18.

2x=36
divide both sides by two and the answer you get is 18.

To check your answer you can just do 18+18 and that equals 36, which is the sum of their ages, as stated in the question.

Please help ASAP HELP!

Answers

Answer:

Step-by-step explanation:

You equal both angles to each other and solve. You should get x=5, the you plug in x giving you 44 for both angles and 88 for ABC

Use the domain and range of each of the following relations to determine which is a function.
{(-4,3), (-2,-1), (-4,8)}
{-4, 3), (-2.-1), (-7, 8)}
{-4,-2,-7, 7}
{-4,3). (-2, -1). (-2, -8), (-7,8)}

Answers

Answer:

A) Not a function

B) Function

C) Function

D) Not a function

Step-by-step explanation:

If the relation has two of the same x-values (that equal different y-values), it is not a function. In other words, if each input value leads to only one output value, classify the relation as a function.

{(-4,3), (-2,-1), (-4,8)}  = Not a function

{-4, 3), (-2.-1), (-7, 8)}  = Function

{-4,-2,-7, 7} = Function (I think?)

{-4,3). (-2, -1). (-2, -8), (-7,8)}= Not a function

-1 2/3 divided by 6 need helo asap

Answers

Answer:

-5/18

Step-by-step explanation:

-1 2/3 is equal to -5/3 and if you follow the keep change flip rule, keep -5/3 change the division sign to multiply and then flip the fraction (6/1 to 1/6) and then multiply.

-5/3 * 1/6 = -5/18

At a local festival, general admission was $3 for students and $5 for adults. 331 people came to the festival and they sold a total of $1431 tickets. How many students came to the festival?

Answers

Answer:112

Step-by-step explanation:

I did it and we doing the same test rn haha. What did you get for the grant one?

How do you do this question?

Answers

4 Answers: A, C, E, and F

================================================

Explanation:

Choice A is true assuming we have [tex]a_n = (-1)^n*b_n[/tex]

In this case, [tex]a_n = (-1)^n*\frac{1}{\sqrt{n}}[/tex] and [tex]b_n = \frac{1}{\sqrt{n}}[/tex]

--------

Choice B is false. See choice A above.

--------

Choice C is true. The sequence [tex]\{b_n\}[/tex] is decreasing. As n gets larger, [tex]b_n[/tex] gets smaller. This is because the denominator is growing larger with the numerator held constant.

--------

Choice D is false. This contradicts choice C.

--------

Choice E is true since the denominator is growing forever

This is similar to  [tex]\displaystyle \lim_{n \to \infty} \frac{1}{n} = 0[/tex]

--------

Choice F is true due to choices C and E being true.  

--------

Choice G is false because it contradicts choice F.

240 in a ratio of 3:5?

Answers

ANSWER: let the ratios are 3x and 5x
therefore,3x+5x=240
8x=240
x=30
so,3x=3×30=90
5x=5×30=150
so,we divide 240 in 90 and 150 to get ratio 3:5

The number who needs to be made into a ratio = 240

Total number of parts = 3 + 5

= 8 parts

Each part = 240 ÷ 8

= 30

Then three parts = 30 × 3 = 90

Five parts = 30 × 5 = 150

Then , the ratio will be = 90 : 150

Therefore , 240 in a ratio of 3 : 5 = 90 : 150 .

Write the equation of a line that passes through two points (3, 4) and (4, -2).

Answers

Answer:

y=-6x+22

Step-by-step explanation:

Equation is declining so its a negative

Mid point on x axis between the two is 22

Help me please does anyone know this answer

Answers

Answer:

There are 150 new employees in the sample space.

There are 30 new employees in each event.

There is a 20% probability that you choose a new employee that has been assigned to orientation group C

Step-by-step explanation:

The value of y is directly PROPORTIONAL to the value of x. If y=44 when x= 240, what is the value of y when x=84?

Answers

Answer:    y = 15.4

If you need the answer in fraction form, then it would be 77/5

This is equivalent to the mixed number 15 & 2/5

======================================================

Work Shown:

y = k*x ..... general direct proportion equation

44 = k*240 .... plug in x = 240 and y = 44

240k = 44

k = 44/240

k = 11/60 .... divide both parts by 4

y = k*x   .... go back to the general form

y = (11/60)x .... plug in the k value we found earlier

y = (11/60)*84 .... plug in x = 84

y = 15.4

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

Extra info:

15.4 = 15 + 0.4

15.4 = 15 + 4/10

15.4 = 15 + 2/5

15.4 = 15 & 2/5 .... mixed number form

and

15.4 = 15 + 2/5

15.4 = 75/5 + 2/5

15.4 = (75+2)/5

15.4 = 77/5 ... improper fraction

Find an equation of the circle that has center (-6, 4) and passes through (4, -5).

Answers

Answer:

waala kang jowa sabi ko

Solve the equation 3(x+1 )-2=x+5

Answers

Answer:

x=2

Step-by-step explanation:

first, let's distribute.

3(x+1)-2=x+5

3x+3-2=x+5

then, let's combine like terms.

3x+1=x+5

now, we subtract x on both sides.

2x+1=5

subtract 1 on both sides.

2x=4

divide by 2 on both sides.

x=2

The answer to the equation is x=2
Here’s how:

3x-29=6x-7 what is x

Answers

Answer:

Step-by-step explanation:

You want to get x on one side and the constants on the other. First subtract both sides by 3x to get:

-29 = 3x - 7

Now add 7 to both sides to get:

-22 = 3x

Divide each side by 3 to get:

x = -22/3

3x-29=6x-7
-6. -6
-3x-29=-7
+29 +29
-3x=22
x=-22/3

what are the measures of angles a,b,c ?

Answers

Answer:

a=30 ,  b=60,  c=105

Step-by-step explanation:

a=30 [Being vertically opposite angle]

Now,

      a+b+90=180 [Being the sum of interior angles of a triangle]

or, 30+b+90=180

or, b+120=180

or, b=180-120

so, b= 60

Again,

     c+75= 180 [Being linear pair]

or, c=180-75

so, c= 105

I needdddd helpppp !! Quickkkk !!

P = 2l + 2w

A rectangle has a width of x and a length of
x + 2. The perimeter is 20 inches. Find the value of the width and the length of the rectangle.

A. Width=9, Length=11
B. Width=6, Length=8
C. Width=4,Length=6
D. Width=3, Length=5

Answers

Answer:

width= 4, length= 6

Step-by-step explanation:

use perimeter formula and substitute values

so formula becomes:

20= 2(x+2) + 2(x)

expand the brackets and that gives us

20= 2x+4 +2x

so

16=4x

x= 4

so width is x which is 4

and length is x+2 which is 6

60 5/6 + 54 1/3 + 56 1/6 + 59 1/3 pls help

Answers

Answer: Is 174.333333333 Hope this helps! and pls give me brainliest i need it

Step-by-step explanation:

Which of the following is a point on the graph of y-7=3(x-5)

Answers

Answer: (5, 7)

Explanation: The formula for point slope form is,

y2 - y1 = m (x2 - x1)

When you look at the values that have been substituted in, you can see the the x value is 5 and the y value is 7.

When you look at the formula, you can se

Which is the best approximate solution of the system of linear equations y=1.5x -1 and y=1

Answers

Answer:

(1 1/3, 1)

Step-by-step explanation:

1.5x-1=1

1.5x=2

x=1 1/3

y=1

(1 1/3, 1)

The length of a rectangle is four more than three times it’s width. The perimeter is 64 inches

Answers

Answer:

Length: 25, Width: 7

Step-by-step explanation:

Let the width be represented by w. We can then assume that the length is equivalent to 3w+4

So, we can set the equation 2(3w+4)+2(w). Simplify to 8w+8=64

Simplify the equation and solve for w, which is 7

Plug into the the length, which is 3w+4

Answer:

Length: 25 inches

Width: 7 inches

Step-by-step explanation:

Perimeter = 2L + 2W

Length: 3w + 4

Width: w

64 = 2(3w + 4) + 2w

64 = 6w + 8 + 2w

64 = 8w + 8

56 = 8w

w = 7

Length: 3(7) + 4 = 25

Width: 7

Bill hikes 8 miles in 3 hours. At this rate. how many miles will he hike after 2 hours?

Answers

Answer:

5 1/3 miles

Step-by-step explanation:

We can use a ratio to solve

8 miles      x miles

------------ = --------

3 hours         2 hours

Using cross products

8*2 = 3x

16 = 3x

Divide by 3

16/3 = 3x/3

5 1/3 miles =x

Answer: [tex]5 \frac{1}{3}[/tex] miles

For the rate of 8 miles in 3 hours, you divide.

For the rate of - miles in 2 hours, multiply.

8 x 2 = 3x

16 = 3x

Now, we have to divide by 3x by 3.

3x divided by 3 = 5 1/3

Answer = 5 1/3

HELP QUICK WILL GIVE BRAINLIEST

Answers

Can’t see what’s that

Answer:

I gave the answers to the first four problems.

Step-by-step explanation:

1) LAB=40°

2) angle 3= 57°

3) x=25°

4) y= 29°

Please help hurry!! This is due in 30 minutes and I need help with domain and range.

Answers

min = -infinity
max = infinity
domain = x ≠ 1
range = y ≠ 0
function = 1/x (rational function)
line of symmetry = none
continuous = yes
x-intercepts = none
y-intercepts = (0,-1)

If -2 + v = 16, then v = 14

Answers

Answer: deduction???

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

Answer:

That is incorrect.

Step-by-step explanation:

-2+v=16

+2     +2

v=18

v will not equal 14; it will equal 18

carol feeds her bird the same amount of food every day. over the past 7 days, her bad of bird food has decreased by 1 3/4 cups.

Answers

Answer:

12.25 or 12 1/4

Step-by-step explanation:

Every day, the bird at 1.75 or 1 and 3/4. so, this would also equal to 1.75*1 day.

So, 7 days, the bird would eat, 1.75*7 days.

1.75*7=12.25

Answer:

12.25 or 12 1/4

Step-by-step explanation:

Every day, the bird at 1.75 or 1 and 3/4. so, this would also equal to 1.75*1 day.

So, 7 days, the bird would eat, 1.75*7 days.

1.75*7=12.25

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