A certain test preparation course is designed to help students improve their scores on the LSAT 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 5 students' scores on the exam after completing the course: 16, 21, 22, 12, 22
Using these data, construct a 90% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Answers

Answer 1

Answer:

The critical value used is [tex]T_c = 2.132[/tex]

The 90% confidence interval for the average net change in a student's score after completing the course is (14.357, 22.843).

Step-by-step explanation:

Before building the confidence interval, we need to find the sample mean and the sample standard deviation.

Sample mean:

[tex]\overline{x} = \frac{16+21+22+12+22}{5} = 18.6[/tex]

Sample standard deviation:

[tex]s = \sqrt{\frac{(16-18.6)^2+(21-18.6)^2+(22-18.6)^2+(12-18.6)^2+(22-18.6)^2}{4}} = 4.45[/tex]

Confidence interval:

We have the standard deviation for the sample, so the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So

df = 5 - 1 = 4

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 4 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 2.132. The critical value used is [tex]T_c = 2.132[/tex]

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.132\frac{4.45}{\sqrt{5}} = 4.243[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 18.6 - 4.243 = 14.357

The upper end of the interval is the sample mean added to M. So it is 18.6 + 4.243 = 22.843.

The 90% confidence interval for the average net change in a student's score after completing the course is (14.357, 22.843).


Related Questions

1.8>4.7+w

Does anyone know what this may be ? Thank you very much .

Answers

Answer:

-2.9 > w

Step-by-step explanation:

1.8>4.7+w

Subtract 4.7 from each side

1.8-4.7>4.7-4.7+w

-2.9 > w

Answer:

w = -2.9

Step-by-step explanation:

Which of the following is a monomial?
A. 8x^2 +7x+3
B. √x-1
C. 9/x
D. 7x​

Answers

Answer:

7x is monomial according to question.

Measure and record the lengths of the sides of ABC and FGH.

Answers

Answer:

can you please send the picture of the diagram.

Step-by-step explanation:

Answer:

ABC:

AB-5 units

BC-12.65 units

AC-15 units

FGH:

FG-5 units

GH-12.65 units

FH-15 units

Step-by-step explanation:

PLATO SAMPLE ANSWER

Please help me with this!

Answers

9514 1404 393

Answer:

7x -5 = 9x = 2

Step-by-step explanation:

A) If we let x represent "a number", then "seven times a number" is 7x. When 5 is subtracted from that, we have ...

  7x -5 . . . . . 5 subtracted from 7 times a number

This is said to be 9, so ...

  7x -5 = 9 . . . . . . . 5 from 7 times a number is 9. Your equation.

__

B) To solve this, we can add 5 to both sides. This eliminates the constant term we don't want on the left.

  7x = 14

Now, we can divide by 7, the coefficient of x that we don't want.

  x = 14/7

  x = 2

What is the domain of f(x)=square root of 9-14x

Answers

Answer: 6.9

Step-by-step explanation:



The rate of interest on a loan is increased from 8.5% to 9% and the debtor has to pay Rs.25 more a year.how much is the loan.

Answers

Answer:

Step-by-step explanation:

0.09x - 0.085x = 25

0.005x = 25

x = 5000

The loan is for Rs 5000

Let S be a sample of size 31 from a normally distributed population Omega . It is given that the average of the data in S is 120 and the standard deviation is 18. Construct a 90% confidence interval [a, b] for the population mean based on the data in the sample.

Answers

Answer:

48 NO seña hfjxsmisns sisbxbd

Step-by-step explanation:

nzhejsbxbddndbhwksdyanvxydjd4mnnneknwnennnnnn

Betadine solution is a 10% povidone-iodine solution. Express this strength both as a fraction and as a ratio.

Answers

Step-by-step explanation:

Fraction =

[tex] \frac{10}{100} = \frac{1}{10} [/tex]

Ratio is 1 : 10

Instructions: State what additional information is required in order
to know that the triangles in the image below are congruent for the
reason given
Reasory. ASA Postulate

Answers

Answer:

ACB = JCB

Step-by-step explanation:

ASA means angle - (included) side - angle.

we have one angle confirmed.

we have the connected side BC confirmed (the diagram shows that the side is shared, so it is not only congruent, it is actually identical).

now we need confirmation for the angle at the other end point of that side.

Michael wants to buy an efficient Smart car that according to the latest EPA standards gets 33 mpg in the city and 40 mpg on the highway. The car that Michael picked out costs $18,560. His dad agreed to purchase the car if Michael would pay it off in equal monthly payments for the next 64 months. The equation y= - 290x +18,560 represents the amount, y
(in dollars), that Michael owes his father after x months.

(a) How much does Michael owe his dad after 3 months?

(b) Determine the slope of the line and interpret its meaning in the context of this problem.

(c) Interpret the meaning of the slope in the context of this problem.


The amount Michael owes his father increases or decreases by ___ per month.

Answers

Answer:

17690

Step-by-step explanation:

The amount Michael owes is given by :

y = - 290x +18,560

x = number of months ; y = amount owed

Amount owed after 3 months :

Put x = 3 in the equation :

y= - 290(3) +18,560

y = - 870 + 18560

y = 17690

According to the general form of a linear equation :

y = mx + c

Where, m = slope ; c = intercept

The slope = - 290 ; Intercept = 18560

Slope is the change in y per unit change in x ; The slope means that amount owed, y decreases by 290 per month

The intercept shows that the original amount borrowed is 18560

Amount Michael owes his father decreases by 290 per month.

which polygon will NOT tessellate a plane?

Answers

Step-by-step explanation:

the answer is regular octagon

i think

Type 7.2e-4 as a floating-point literal but not using scientific notation, with a single digit before and five digits after the decimal point.

Answers

Answer:

A

Step-by-step explanation:i did the test

The value of the floating point number is A = 0.00072

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

A = 7.2e⁻⁴

On simplifying the equation , we get

A = 7.2 x 10⁻⁴

The value of the decimal point is moved 4 units to the left , so

The number A is A = 0.00072

Hence , the floating point number is A = 0.00072

To learn more about equations click :

https://brainly.com/question/19297665

#SPJ2

urgent please help! will give brainliest

Answers

Answer:

The answer is A

Step-by-step explanation:

(-2,-3) (3,-4) (0,-1) (-7,3)

inverse means the opposite signs

(2,3) (-3,4) (0,1) (7,-3)

Select the correct answer. Which expression is equivalent to the given expression? Assume the denominator does not equal zero.​

Answers

Answer:

Step-by-step explanation:

You have not provided the answers to choose from.

The expression can be simplified to δ⁴/a, but I cannot tell if that is one of the choices.

Can some please help please thank you

Answers

Answer:

b the answer

Step-by-step explanation:

The answer to this is D

Can someone do these please? ❤️

Answers

Answer:

-49

8

Step-by-step explanation:

-196/4 =

-49

(3+u)^2

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

8

Let u=5

(3+5)^2

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

8

(8)^2

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

8

64

-----

8

8

1->dương vô cùng 1/x*(9+lnx^2)dx

Answers

It looks like you are trying to compute the improper integral,

[tex]I = \displaystyle\int_1^\infty \dfrac{\mathrm dx}{x(9+\ln^2(x))}[/tex]

or some flavor of this. If this interpretation is correct, substitute u = ln(x) and du = dx/x. Then

[tex]I = \displaystyle\int_0^\infty \dfrac{\mathrm du}{9+u^2} \\\\ = \frac13\arctan\left(\frac u3\right)\bigg|_{u=0}^{u\to\infty} \\\\ = \frac13\lim_{u\to\infty}\arctan\left(\frac u3\right) \\\\ = \frac13\times\frac\pi2 = \boxed{\frac\pi6}[/tex]

How many ways are there to choose three distinct integers between 1 and 20 inclusive such that the numbers form an arithmetic sequence?
*please try to answer by tomorrow/

Answers

Answer:

probability of the product of the chosen integers being a multiple of 3 is P(E)= 1 - (91/285)

=194/285 or 0.6807.

Step-by-step explanation:

The sample space of all possible choices of three integers from the set {1,2,…..,20} has C(20,3) = (20×19×18)/3! elements.

The complement of the event space E consists of all possible choices of three integers from the complement of the set of all the multiples of 3 in the above set because the product of the chosen integers is a multiple of 3 if and only if at least one of them is a multiple of 3. Hence we have to choose three elements from the set {1,2,4,5,7,8,10,11,13,14,16,17,19,20} which has 14 elements.

Hence

|E'| = C(14,3)

= 14×13×12/3!.

Therefore probability P(E')

= |E'|/|S|

= (14×13×12)/(20×19×18)

= (14×13×2)/(20×19×3)

=(7×13)/(5×19×3)

= 91/285.

Therefore the required probability of the product of the chosen integers being a multiple of 3 is P(E)= 1 - (91/285)=194/285 or 0.6807.

what is the perfect square of 96​

Answers

Step-by-step explanation:

We determined above that the greatest perfect square from the list of all factors of 96 is 16.

a playing card is chosen at random from a standard deck of cards. what is the probability of choosing 5 of diamonds or one jack

Answers

Answer:

1/52

Step-by-step explanation:

90 units needed 8per case

Answers

Are you asking how much cases is needed to to reach the 90 units? If yes then 90/8 which would give you 11.25. But since it’s by case then round up to get 12 cases. I think I answered it wrong but

Identify the first 4 terms in the arithmetic sequence given by the explicit formula ƒ(n) = 8 + 3(n – 1).

Answers

Step-by-step explanation:

simple formula application :

a1 = 8 + 3×(1-1) = 8

a2 = 8 + 3×(2-1) = 11

a3 = 8 + 3×(3-1) = 14

a4 = 8 + 3×(4-1) = 17

...

please help me with this

Answers

9514 1404 393

Answer:

  92°

Step-by-step explanation:

The "givens" tell you the E and F are midpoints of their respective segments. That means EF ║ AB and angles DBF and EFC are "corresponding" angles with respect to transversal BC and those parallel lines. Corresponding angles are congruent, so ...

  m∠DBF = m∠EFC = 92°

Find the lengths of the other two sides of the isosceles right triangle

Answers

Answer:

h²=p²+b²

(7√2)²=x²+x²

(49×2)=2x²

2x²=49ײ

x²=49×2/2

x²=49

x=√49=7

x=7

OAmalOHopeO

The answer is 7 I’m quite sure

find the missing side length in the image below​

Answers

Answer:

The missing side length is of 5.

Step-by-step explanation:

The sides are proportional, which means that the missing side can be found using a rule of three.

x - 10

3 - 6

Applying cross multiplication:

[tex]6x = 30[/tex]

[tex]x = \frac{30}{6} = 5[/tex]

The missing side length is of 5.

Find the volume V of the solid obtained by rotating the region bounded by the given curves about the specified line.
y2 = 2x, x = 2y;
about the y-axis
b) Sketch the region
c) Sketch the solid, and a typical disk or washer.

Answers

Answer:

V = 34,13*π   cubic units

Step-by-step explanation: See Annex

We find the common points of the two curves, solving the system of equations:

y²  = 2*x                           x = 2*y  ⇒  y = x/2

(x/2)² = 2*x

x²/4 = 2*x

x  =  2*4         x  = 8      and   y = 8/2       y = 4

Then point  P ( 8 ;  4 )

The other point Q is  Q ( 0; 0)

From these  two points, we get the integration limits for dy ( 0 , 4 )are the integration limits.

Now with the help of geogebra we have: In the annex segment ABCD is dy then

V = π *∫₀⁴ (R² - r² ) *dy   =  π *∫₀⁴ (2*y)² - (y²/2)² dy =  π * ∫₀⁴ [(4y²) - y⁴/4 ] dy

V = π * [(4/3)y³ - (1/20)y⁵] |₀⁴

V =  π * [ (4/3)*4³ - 0 - 1/20)*1024 + 0 )

V = π * [256/3  - 51,20]

V = 34,13*π   cubic units

A jewerly store sold a 7.4 gold necklace for 162.18 how much was the necklace worth per gram? round your answer to the nearest tenth

Answers

Answer:

$21.9 per gram

Step-by-step explanation:

Take the total price and divide by the number of grams

$162.18/7.4 grams

$21.91621 per gram

Rounding to the nearest tenth

$21.9 per gram

Answer:

$21.90 per gram (to the nearest tenth)

Step-by-step explanation:

Given information:

Weight of gold necklace = 7.4 gPrice of gold necklace = $162.18

To find how much the necklace was worth per gram, divide the total cost by the number of grams:

[tex]\sf Worth\:per\:gram = \dfrac{\$162.18}{7.4\:g}=\$21.91621622... \:per\:gram[/tex]

Therefore, the necklace is worth $21.90 per gram (to the nearest tenth).

How many hours will it take to complete a 45-km bike ride if you go 12km per hour the whole time?

Answers

Answer:

3.75 hours

Step-by-step explanation:

d = rt

where d is the distance, r is the rate and t is the time

45 = 12 t

Divide each side by 12

45/12 = t

3.75 hours = t

A construction crane lifts a bucket of sand originally weighing 145 lbs at a constant rate. Sand is lost from the bucket at a constant rate of .5lbs/ft. How much work is done in lifting the sand 80ft?

Answers

Answer: [tex]10,000\ lb.ft[/tex]

Step-by-step explanation:

Given

Initial weight of the bucket is [tex]145\ lb[/tex]

It is lifted at constant rate and rate of sand escaping is [tex]0.5\ lb/ft[/tex]

At any height weight of the sand is [tex]w(h)=145-0.5h[/tex]

Work done is given by the product of applied force and displacement or the area under weight-displacement graph

from the figure area is given by

[tex]\Rightarrow W=\int_{0}^{80}\left ( 145-0.5h \right )dh\\\\\Rightarrow W=\left | 145h-\dfrac{0.5h^2}{2} \right |_0^{80}\\\\\Rightarrow W=\left [ 145\times 80-\dfrac{0.5(80))^2}{2} \right ]-0\\\\\Rightarrow W=11,600-1600\\\\\Rightarrow W=10,000\ lb.ft[/tex]

Of the travelers arriving at a small airport, 60% fly on major airlines, 20% fly on privately owned planes, and the remainder fly on commercially owned planes not belonging to a major airline. Of those traveling on major airlines, 50% are traveling for business reasons, whereas 70% of those arriving on private planes and 80% of those arriving on other commercially owned planes are traveling for business reasons. Suppose that we randomly select one person arriving at this airport.

What is the probability that the person
a. is traveling on business?
b. is traveling for business on a privately owned plane?
c. arrived on a privately owned plane, given that the person is traveling for business reasons?
d. is traveling on business, given that the person is flying on a commercially owned plane?

Answers

Answer:

a) 0.55 = 55% probability that the person is traveling on business

b) 0.14 = 14% probability that the person is traveling for business on a privately owned plane.

c) 0.2545 = 25.45% probability that the person arrived on a privately owned plane, given that the person is traveling for business reasons.

d) 0.2 = 20% probability that the person is traveling on business, given that the person is flying on a commercially owned plane.

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

Question a:

50% of 60%(major airlines)

70% of 20%(privately owned airplanes)

80% of 100 - (60+20) = 20%(comercially owned airplanes). So

[tex]p = 0.5*0.5 + 0.7*0.2 + 0.8*0.2 = 0.55[/tex]

0.55 = 55% probability that the person is traveling on business.

Question b:

70% of 20%, so:

[tex]p = 0.7*0.2 = 0.14[/tex]

0.14 = 14% probability that the person is traveling for business on a privately owned plane.

Question c:

Event A: Traveling for business reasons.

Event B: Privately owned plane.

0.55 = 55% probability that the person is traveling on business.

This means that [tex]P(A) = 0.55[/tex]

0.14 = 14% probability that the person is traveling for business on a privately owned plane.

This means that [tex]P(A \cap B) = 0.14[/tex]

Desired probability:

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.14}{0.55} = 0.2545[/tex]

0.2545 = 25.45% probability that the person arrived on a privately owned plane, given that the person is traveling for business reasons.

Question d:

Event A: Commercially owned plane.

Event B: Business

80% of those arriving on other commercially owned planes are traveling for business reasons.

This means that:

[tex]P(B|A) = 0.2[/tex]

0.2 = 20% probability that the person is traveling on business, given that the person is flying on a commercially owned plane.

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