SAT verbal scores are normally distributed with a mean of 430 and a standard deviation of 120 (based on data from the College Board ATP). (a) If a single student is randomly selected, find the probability that the sample mean is above 500. (b) If a sample of 35 students are selected randomly, find the probability that the sample mean is above 500. These two problems appear to be very similar. Which problem requires the application of the central limit theorem, and in what way does the solution process differ between the two problems?

Answers

Answer 1

Using the normal distribution and the central limit theorem, it is found that there is a:

a) 0.281 = 28.1% probability that the sample mean is above 500.

b) 0.0003 = 0.03% probability that the sample mean is above 500.

In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

It measures how many standard deviations the measure is from the mean.  After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X. By the Central Limit Theorem, the sampling distribution of sample means of size n has standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

In this problem:

The mean is of 430, hence [tex]\mu = 430[/tex].The standard deviation is of 120, hence [tex]\sigma = 120[/tex].

Item a:

The probability is the p-value of Z when X = 500, hence:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{500 - 430}{120}[/tex]

[tex]Z = 0.58[/tex]

[tex]Z = 0.58[/tex] has a p-value of 0.719.

1 - 0.719 = 0.281

0.281 = 28.1% probability that the sample mean is above 500.

Item b:

Sample of 35, hence [tex]n = 35, s = \frac{120}{\sqrt{35}}[/tex]

Then:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{500 - 430}{\frac{120}{\sqrt{35}}}[/tex]

[tex]Z = 3.45[/tex]

[tex]Z = 3.45[/tex] has a p-value of 0.9997.

1 - 0.9997 = 0.0003

0.0003 = 0.03% probability that the sample mean is above 500.

To learn more about the normal distribution and the central limit theorem, you can take a look at https://brainly.com/question/24663213


Related Questions

What’s a rational number between -1/6 and 1/9

Answers

Answer:

LCM of 6 and 9 are 18

1/6 = 1×3/6×3

= 3/18

= 3×10/18×10

= 30/180

1/9 = 1×2/9×2

= 2/18

=2×10/18×10

= 20/180

therefore rational no.s between 1/6 & 1/9 are

21/180,22/180,23/180,24/180,25/180,26/180,27/180,28/180,29/180

Step-by-step explanation:

sorry if im wrong

Answer:

1/18.

Step-by-step explanation:

-1/6 = -3/18 and 1/9 = 2/18

so one rational number between these values is  1/18.

Over the course of 12 hours the temperature changes a tour of -16°C what is the average change in temperature in one hour

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Answer:

- 1 1/3 degree

Step-by-step explanation:

- 16 / 12

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It's probably 52 or 40.

#10) Mrs. Sommer states that angle I is 65 degrees. Is she correct? why or why not​

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Answer: Mrs. Somner is correct.

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If y/x does not always equal the same

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Step-by-step explanation:

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A line with a slope of 3 passes through the point (0, -10). What is its equation in
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Answers

[tex](\stackrel{x_1}{0}~,~\stackrel{y_1}{-10})\qquad \qquad \stackrel{slope}{m}\implies 3 \\\\\\ \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{(-10)}=\stackrel{m}{3}(x-\stackrel{x_1}{0}) \\\\\\ y+10=3x\implies \stackrel{\textit{slope-intercept form}}{y=3x-10}[/tex]

Find the area of the figure. hi​

Answers

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We figure 25 people will attend if it rains and 70 people will attend if it does not rain. The weather forecast indicates that there is a 20% chance of rain that day. What is the expected number of people who will attend the party?

Answers

Answer:

34

Step-by-step explanation:

20% of 70 + 80% of 25 = 14 + 20 = 34.

Answer:

61

Step-by-step explanation:

Assuming a linear relationship between the percent chance for rain and the number of attendees, the number is 20% of the way from 70 (0% chance) to 25 (100% chance).

The expected number of people with a 20% chance of rain would be 61.

(hope it helps)

50 POINTS
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Answers

Taking 2x from both sides gives
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Dividing through by 3 gives us

y = -2x/3 + 2

Isaac bought 7 chicken wings for $12.60. How much does each wing cost?

Answers

Answer:

Each chicken wing costs $1.80.

Explanation:

To find the cost for each wings, you need to split the money by 7 which is: 12.60/ 7

this gives us:

1.80

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Answer:

[tex] \frac{2}{5} > \frac{1}{6} [/tex]

Answer: B. >

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The polygons are similar. The area of one polygon is given. Find the area of the other polygon.

Answers

Answer:

108 ft²

Step-by-step explanation:

For the polygon on the left, we are given the length of one side (3 ft) and the total area (27 ft²). With this information, we can determine the length of the other side - 9 ft. I found this by dividing 27 ft² by 3 ft, giving me the final result of 9 ft.

Next, we have to find the other side of the polygon on the right so we can ultimately determine its area. It looks like there is a scale factor of 2 between the two polygons, since 3 × 2 = 6. We know that the bottom side of the left polygon is 9, so multiplying 9 by 2 should give us the bottom side of the polygon on the right. 9 × 2 = 18.

Now, we have the side lengths for the polygon on the right and can determine its area. What is 6 ft × 18 ft? Well, the answer is 107 ft², and this is the answer to the question.

Hopefully that's helpful! :)

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Answers

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(a) The perimeter of a rectangular garden is 320 m.
If the width of the garden is 74 m, what is its length?

(b) The area of a rectangular window is 5723 cm?
If the length of the window is 97 cm, what is its width?
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Answers

Answer:

86 m, 59 cm

Step-by-step explanation:

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SOMEONE PLEASE HELP QUICKLY

A commercial claims that 8 out of 10 dentists recommend a certain brand of toothpaste. To test this claim, a random sample of 85 dentists is obtained. Of these 85 dentists, 73 indicated that they recommend that brand of toothpaste. Using a significance level of 5%, test the claim to see if the proportion of dentists who recommend this toothpaste is not 8 of 10.



a) State the null and alternative hypotheses

b) State the p value

c) Make a conclusion about the claim

Answers

Answer:

rgb

Step-by-step explanation:

wrtbtrb

a) The null hypothesis is: p = 0.8 and the alternative hypothesis is p ≠ 0.8.

b) p-value is 0.0838

c) We accept the null hypothesis

What are null and alternative hypothesis?

The null hypothesis of a test always predicts no effect or no relationship between variables, while the alternative hypothesis states your research prediction of an effect or relationship.

What is p-value?

A p-value is a statistical measurement used to validate a hypothesis against observed data.

a. Let p be the proportion of 8 out of 10 dentists.

The null hypothesis is

[tex]H_0 : p=\frac{8}{10}=0.8[/tex]

The alternative hypothesis is

[tex]H_1:p\neq 0.8[/tex]

b. The sample proportion [tex]\hat p=\frac{73}{85}\approx 0.86\\[/tex]

Z-score, the test statistic is

[tex]Z=\frac{\hat p-p}{\frac{\sqrt{p(1-p)}}{n} } \\\\Z=\frac{0.86-0.8}{\frac{\sqrt{0.8(1-0.8)}}{85} }\\ \\Z=\frac{0.06}{0.043386}\\ \\Z=1.3829\\\\Z\approx 1.38[/tex]

P(Z > 1.38) = 1 - P(Z < 1.38)

∴ P(Z > 1.38) = 1 - 0.9162 = 0.0838

p-value is 0.0838

c. Since the p-value is greater than the level of significance α=0.05, we reject the alternative hypothesis and accept the null hypothesis

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Answer:

Answers given in the photo

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option a .......

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10

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Given this equation in slope-intercept form…
y = 2x + 5
Identify or solve for the following:
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y-intercept
x-intercept
Independent variable
Dependent variable
Domain
Range
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What is the rate of change of the function above?

Answers

Answer:

y = m x + b    standard form of straight line

y = 2 x + 5

The slope is m and = 2

the y intercept is 5  because when x = o y = 5

if y = 0 then x = -2/5 and would be the x intercept

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14 minutes at 100 degrees

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Answer:

67 quarters

Explanation:

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Answer:

$79.64

Step-by-step explanation:

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Answer:

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Answers

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Answer:

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Step-by-step explanation:

rise over run

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Answers

Answer:

x > 5

Step-by-step explanation:

multiply the fractions, break up the fraction, group like terms, convert integer into a fraction, combine the fraction, combine the numerator, etc. hope this helps.

Riley is saving up to buy a new television. She needs a total of $966.42. Riley has saved $200.92 already and earns $76.55 per week at her job. How many weeks does Riley need to work to save enough money to buy the new television

Answers

Answer:

10 weeks

Step-by-step explanation:

76.55x+200.92=966.42

76.55x=966.42-200.92

76.55x=765.5

x=765.5/76.55

10

which statement best describes the first step to the equation -11-3x=44-2x

A. add 3 to both sides

B add 2 to both sides

C.get the variables on one side

Answers

C. get the variables on one side

Get the variables on one side statement best describes the first step to the equation -11-3x=44-2x

What is Equation?

Two or more expressions with an Equal sign is called as Equation.

The given equation is  -11-3x=44-2x

Minus eleven minus three x equal to forty four minus two times of x

To solve this, we need to seperated the variable on one side

-3x+2x=44+11

-x=55

x=-55

Get the variables on one side is the  first step to the equation -11-3x=44-2x

Hence, get the variables on one side statement best describes the first step to the equation -11-3x=44-2x

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https://brainly.com/question/10413253

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I will mark as brainliest if answer is correct.
Which ordered pair is a solution to the system of inequalities?
y≥2x-1
y<4x

A. (2,6)

B. (3,2)

C. (3,4)

D. (2,8)​

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A. (2,6) is a solution to the system of inequalities because it's inside the double shaded area.
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