# Florida SouthWestern State College Statistics Worksheet

3/26/22, 12:00 PMStudy Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Study Guide #3: Chapter 8 through Chapter 9

Due Apr 3 at 11:59pm

Points 55

Questions 55

Available Jan 5 at 12am – Apr 3 at 11:59pm 3 months

Time Limit 120 Minutes

Allowed Attempts Unlimited

Instructions

Students have unlimited attempts for this assignment. The highest score on this assignment will be used

to calculate the overall course score.

The student t distribution table and the standard normal table (see below) will be posted in the Test

header. If you use INVT then you won’t need the student t distribution table. If you use NORMALCDF

and INVNORM then you won’t need the table standard normal table.

External webcams must be used during all proctored exams. The external webcam must be positioned

so that the instructor can view your desktop.

During Proctored Test #3: Chapter 8 through Chapter 8, students will have 120 minutes to complete the

exam and will only be able to use the following:

two notecards (3″ by 5 “, front and back)

scratch paper

a calculator

https://artofstat.com/web-apps

Microsoft Excel

(https://artofstat.com/web-apps)

Chrome web browser

Need Technical Support during the Test? Contact Proctorio 24/7 by:

Live Chat by clicking the Proctorio extension (shield icon in Chrome)

Email support@proctorio.com (mailto:support@proctorio.com)

Student T Distribution Table

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Normal Distribution Table

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Take the Quiz Again

Attempt History

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Attempt 1

less than 1 minute

0 out of 55

Correct answers are hidden.

Score for this attempt: 0 out of 55

Submitted Mar 26 at 12pm

This attempt took less than 1 minute.

Unanswered

Question 1

0 / 1 pts

The Central Limit Theorem is important in statistics because

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

for a large n, it says the population is approximately normal.

for a n 30)

The sampling distribution of the sample mean is generated by repeatedly

taking samples of size n and computing the sample means

The mean of the sampling distribution of the sample mean is equal to the

population mean .

The standard deviation of the sampling distribution of the sample mean is

equal to the population standard deviation

Unanswered

Question 4

0 / 1 pts

One person is randomly selected from a population whose mean is 45

and the standard deviation is 9. What is the probability that the person’s

score is less than 42? Assume the population is normally distributed.

Round answer to 4 decimal places.

Unanswered

Question 5

0 / 1 pts

A random sample of size 81 is selected from a population whose mean is

45 and the standard deviation is 9. Calculate the probability that a sample

mean is less than 42.

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Round answer to 4 decimal places.

HINT: When you randomly select a group (n > 1) then you need to

calculate the standard deviation of the sampling distribution using the

formula:

Unanswered

Question 6

0 / 1 pts

With regards to calculating the probability that the score was less than 42,

what did you notice when the sample size was increased from 1 person to

81 persons?

The area to the left of 42 decreased.

The area to the left of 42 increased.

The area to the left of 42 did not change.

Unanswered

Question 7

0 / 1 pts

One person is randomly selected from a population whose mean is 45

and the standard deviation is 9. What is the probability that the person’s

score is greater than 48? Assume the population is normally distributed.

Round answer to 4 decimal places.

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Unanswered

Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Question 8

0 / 1 pts

A random sample of size 81 is selected from a population whose mean is

45 and the standard deviation is 9. Calculate the probability that a sample

mean is greater than 48.

Round answer to 4 decimal places.

Unanswered

Question 9

0 / 1 pts

With regards to calculating the probability that the score was greater than

48, what did you notice when the sample size was increased from 1

person to 81 persons?

The area to the right of 48 decreased.

The area to the right of 48 increased.

The area to the right of 48 did not change.

Unanswered

Question 10

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0 / 1 pts

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3/26/22, 12:00 PM

Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

One person is randomly selected from a population whose mean is 45

and the standard deviation is 9. What is the probability that the person’s

score is between 42 and 48? Assume the population is normally

distributed.

Round answer to 4 decimal places.

Unanswered

Question 11

0 / 1 pts

A random sample of size 81 is selected from a population whose mean is

45 and the standard deviation is 9. Calculate the probability that a sample

mean is between 42 and 48.

Round answer to 4 decimal places.

Unanswered

Question 12

0 / 1 pts

With regards to calculating the probability that the score was between 42

and 48, what did you notice when the sample size was increased from 1

person to 81 persons?

The area between 42 and 48 decreased.

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

The area between 42 and 48 increased.

The area between 42 and 48 did not change.

Unanswered

Question 13

0 / 1 pts

What changes did you observe in the graph when the sample size was

increased from 1 person to 81 persons?

There were no changes in the graph.

The width of the graph decreased causing the area surrounding the mean

to increase.

The width of the graph increased causing the area surrounding the mean

to decrease.

Unanswered

Question 14

0 / 1 pts

The annual salaries of employees in a large company are approximately

normally distributed with a mean of $50,000 and a standard deviation of

$2000. What is the probability of randomly selecting one employee

whose salary is between $48,000 to $52,000?

Round answer to 4 decimal places.

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Unanswered

Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Question 15

0 / 1 pts

The annual salaries of employees in a large company are approximately

normally distributed with a mean of $50,000 and a standard deviation of

$2000. Suppose 10 employees are randomly selected. What is the

probability that the mean salary is between $48,000 to $52,000?

Round answer to 4 decimal places.

Unanswered

Question 16

0 / 1 pts

The annual salaries of employees in a large company are approximately

normally distributed with a mean of $50,000 and a standard deviation of

$2000. What is the probability of randomly selecting one employee

whose salary is greater than or equal to $52,000?

Round answer to 4 decimal places.

Unanswered

Question 17

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0 / 1 pts

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

The annual salaries of employees in a large company are approximately

normally distributed with a mean of $50,000 and a standard deviation of

$2000. Suppose you randomly select 10 employees. What is the

probability of the mean salary is greater than or equal to $52,000?

Round answer to 4 decimal places.

Unanswered

Question 18

0 / 1 pts

What do you notice when you calculate probabilities associated with a

sampling distribution?

As sample size increases, the probability is higher near the mean of the

distribution.

As sample size increases, the probability is higher in the tails of the

distribution.

As sample size increases, the probability is lower in the tails of the

distribution.

As sample size increases, the probability is lower near the mean of the

distribution.

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Unanswered

Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Question 19

0 / 1 pts

A random sample of 250 students is taken from a population of 4,000

students at the State University for which the overall proportion of males is

0.3. Verify whether the sampling distribution for the proportion of male

students is normally distributed.

The distribution is approximately normal

The distribution is not normal because np(1-p) 0.05N

The distribution is not normal because np(1-p) >10

Unanswered

Question 20

0 / 1 pts

A random sample of 25 students is taken from the population of all parttime students in the United States, for which the overall proportion of

females is 0.6. Verify whether the sampling distribution for the proportion

of part-time female students is normally distributed.

The distribution is approximately normal

The distribution is not normal because n>0.05N

The distribution is not normal because np(1-p)>10

The distribution is not normal because np(1-p) 10

The distribution is not normal because n>0.05N

The distribution is approximately normal.

The distribution is not normal because np(1-p) 10

Yes, because np(1-p) is approximately 28

Yes, because np(1-p) is approximately 302

Yes, because np(1-p)=3573

Unanswered

Question 40

0 / 1 pts

What is the critical value z-score for 94% confidence level?

Round answer to 2 decimal places.

Unanswered

Question 41

0 / 1 pts

What is the critical value z-score for an 82% confidence level?

Round answer to 2 decimal places.

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

0 / 1 pts

Question 42

In a recent health survey, 333 adult respondents reported a history of

diabetes out of 3573 respondents. What is the critical value for a 90%

confidence interval of the proportion of respondents who reported a

history of diabetes? (round to 3 decimal places)

Unanswered

0 / 1 pts

Question 43

In a recent health survey, 333 adult respondents reported a history of

diabetes out of 3573 respondents. Construct a 90% confidence interval of

the proportion of persons who reported a history of diabetes. (round to 3

decimal places)

(

,

)

Answer 1:

(You left this blank)

Answer 2:

(You left this blank)

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Unanswered

Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Question 44

0 / 1 pts

In a recent health survey, 333 adult respondents reported a history of

diabetes out of 3573 respondents. Calculate the margin of error for a

90% confidence interval of the proportion of persons who reported a

history of diabetes. (round to 3 decimal places)

Unanswered

Question 45

0 / 1 pts

Calculate the minimum number of subjects needed for a research study

regarding the proportion of respondents who reported a history of

diabetes using the following criteria:

95% confidence, within 5 percentage points, and a previous estimate of

0.25

Unanswered

Question 46

0 / 1 pts

Calculate the minimum number of subjects needed for a research study

regarding the proportion of respondents who reported a history of

diabetes using the following criteria:

95% confidence, within 5 percentage points, and a previous estimate is

not known

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Unanswered

Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

Question 47

0 / 1 pts

The t critical value varies based on (check all that apply):

the sample size

the confidence level

the sample mean

the sample standard deviation

degrees of freedom (n-1)

Unanswered

Question 48

0 / 1 pts

True or False?

As the sample size increases, the t-scores approach the z-scores

associated with the standard normal distribution.

True

False

Unanswered

Question 49

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0 / 1 pts

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

What is the critical value t-score for a 99% confidence level with 10

degrees of freedom df?

Round answer to 3 decimal places.

Unanswered

Question 50

0 / 1 pts

What is the critical value t-score for a 90% confidence level with a sample

size of 20?

Round answer to 3 decimal places.

Unanswered

Question 51

0 / 1 pts

What is the critical value t-score for a 98% confidence level with a sample

size of 30?

Round answer to 3 decimal places.

Unanswered

Question 52

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Study Guide #3: Chapter 8 through Chapter 9: (Spring 2022-1) STA2023: STATISTICAL METHODS I 805 (21675)

The weights of a random sample of 11 female high school students were

recorded. The mean weight was 110 pounds and the standard deviation

was 17 pounds. If the sampling distribution is known to be approximately

normal then what must be true?

By the central theorem, a sample size of 11 is considered to be sufficiently

large to assume the sampling distribution is approximately normal.

By the central theorem, the population distribution must haven been

normally distributed in order for the sampling distribution to have an

approximate normal distribution.

By the central limit theorem, the population distribution must have been

skewed to the left.

By the central limit theorem, the population distribution must have been

uniformly distributed.

Unanswered

Question 53

0 / 1 pts

The weights of a random sample of 11 female high school students were

recorded. The mean weight was 110 pounds and the standard deviation

was 17 pounds. Construct a 95% confidence interval for the mean weight

of all female students at this high school. Assume that weights are

normally distributed.

Lower Bound

Upper Bound

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Round all answers to 2 decimal places.

Answer 1:

(You left this blank)

Answer 2:

(You left this blank)

Unanswered

Question 54

0 / 1 pts

Using the lower bound and upper bound from the previous problem,

calculate the point estimate and the margin of error E. Then re-express

the confidence interval using the following format:

Round answer to 2 decimal places.

Answer 1:

(You left this blank)

Answer 2:

(You left this blank)

Unanswered

Question 55

0 / 1 pts

Calculate minimum sample size needed to estimate the average salary

earned by FSW alumni with the following criteria:

95% confidence level, sample standard deviation of $1525, and within

$125.

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Quiz Score: 0 out of 55

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