Question 1

We wish to record the results from two six-sided die rolls.How many unique outcomes are possible?

Accepted Answer

A)  15 
B)  36 
C)  30 
D)  64 
A)  15 
B)  36 
C)  30 
D)  64

Question 2

A math professor once claimed that 90% of students pass a particular class of hers.To check this claim, a random sample of 150 students who had taken this class was obtained.It was found that 129 passed the class.If the professor is correct, what is the probability that 129 or fewer of the students in such a sample would have passed the class?

Accepted Answer

A)  0.9484 
B)  0.0516 
C)  0.5516 
D)  0.4484 
A)  0.9484 
B)  0.0516 
C)  0.5516 
D)  0.4484

Question 3

A heavily right-skewed population has a mean of 28 and a standard deviation of 2.What is the probability that a random sample of 5 from this population will average less than 27?

Accepted Answer

A)  0.1314 
B)  0.3085 
C)  0.6915 
D)  We cannot answer this question because the sample size is small and the population is non-normal; the distribution of   cannot be assumed to be normal. 
A)  0.1314 
B)  0.3085 
C)  0.6915 
D)  We cannot answer this question because the sample size is small and the population is non-normal; the distribution of   cannot be assumed to be normal.

Question 4

In the normal process of simple random sampling (SRS), samples are almost always drawn without replacement.Why is this a problem for the assumptions involved with a true SRS?

Accepted Answer

A)  Because the samples are drawn without replacement, there will never be enough samples to accurately calculate a meaningful statistic. 
B)  Because the samples are drawn without replacement, the process is not really random. 
C)  Because the samples are drawn without replacement, the samples are not truly independent, as the probability of one sample is affected by previous selections. 
D)  Because the samples are drawn without replacement, this creates complexity, which violates the assumption of simplicity. 
A)  Because the samples are drawn without replacement, there will never be enough samples to accurately calculate a meaningful statistic. 
B)  Because the samples are drawn without replacement, the process is not really random. 
C)  Because the samples are drawn without replacement, the samples are not truly independent, as the probability of one sample is affected by previous selections. 
D)  Because the samples are drawn without replacement, this creates complexity, which violates the assumption of simplicity.

Question 5

If the population proportion is 0.38, what is   if we calculate   using 20 samples?

Accepted Answer

A)  0.0118 
B)  0.1085 
C)  0.0190 
D)  Because   is small, we cannot calculate   accurately. 
A)  0.0118 
B)  0.1085 
C)  0.0190 
D)  Because   is small, we cannot calculate   accurately.

Question 6

The standard error of a statistic used as an estimator of a population parameter is:

Accepted Answer

A)  the standard deviation of the sampling distribution of the statistic. 
B)  the variance of the sampling distribution of the statistic. 
C)  the same value as the population standard deviation. 
D)  the square root of the population variance. 
A)  the standard deviation of the sampling distribution of the statistic. 
B)  the variance of the sampling distribution of the statistic. 
C)  the same value as the population standard deviation. 
D)  the square root of the population variance.

Question 7

A sample of 82 mice is observed from birth until they are one year old.The total amount of growth experienced by each mouse is recorded.The median amount of growth of these mice is 4.5 cm.In this example, 4.5 cm is a:

Accepted Answer

A)  parameter. 
B)  sampling distribution. 
C)  statistic. 
D)  random variable. 
A)  parameter. 
B)  sampling distribution. 
C)  statistic. 
D)  random variable.

Question 8

An exponential population has parameter λ = 0.012 (hence, μ= 83.33, σ2= 6944.44).What is the probability that a random sample of 41 from this population will average between 81 and 84?

Accepted Answer

A)  0.5199 
B)  0.0160 
C)  0.0000 
D)  0.0913 
A)  0.5199 
B)  0.0160 
C)  0.0000 
D)  0.0913

Question 9

Suppose you are interested in determining the average word length in Lincoln's Gettysburg Address.You decide to estimate this average word length by using a sample of 10 randomly selected words.Which of the following methods should result in a simple random sample of 10 words from the Address?

Accepted Answer

A)  Have a student select 10 "representative" words from a copy of the Address. 
B)  Obtain a copy of the Address on a page of paper.Close your eyes and point the tip of your pencil on the page five times, each time selecting the word that your pencil lands on or nearest. 
C)  Obtain a list of the 268 words in the Address.Number the words.Use a random number generator to determine which 10 words to select. 
D)  Select every 27th word in the Address. 
A)  Have a student select 10 "representative" words from a copy of the Address. 
B)  Obtain a copy of the Address on a page of paper.Close your eyes and point the tip of your pencil on the page five times, each time selecting the word that your pencil lands on or nearest. 
C)  Obtain a list of the 268 words in the Address.Number the words.Use a random number generator to determine which 10 words to select. 
D)  Select every 27th word in the Address.

Question 10

In a recent study, it was reported that the proportion of employees who miss work on Fridays is 0.15, and that the standard deviation of the sample proportion is   .However, the report did not indicate the sample size n.What was the sample size, assuming the Central Limit Theorem holds in this case?

Accepted Answer

A)  26 
B)  58 
C)  102 
D)  204 
A)  26 
B)  58 
C)  102 
D)  204

We wish to record the results from two six-sided die rolls.How many unique outcomes are possible?

A heavily right-skewed population has a mean of 28 and a standard deviation of 2.What is the probability that a random sample of 5 from this population will average less than 27?

In the normal process of simple random sampling (SRS), samples are almost always drawn without replacement.Why is this a problem for the assumptions involved with a true SRS?

If the population proportion is 0.38, what is if we calculate using 20 samples?

The standard error of a statistic used as an estimator of a population parameter is:

A sample of 82 mice is observed from birth until they are one year old.The total amount of growth experienced by each mouse is recorded.The median amount of growth of these mice is 4.5 cm.In this example, 4.5 cm is a:

An exponential population has parameter λ = 0.012 (hence, μ= 83.33, σ2= 6944.44).What is the probability that a random sample of 41 from this population will average between 81 and 84?

Suppose you are interested in determining the average word length in Lincoln's Gettysburg Address.You decide to estimate this average word length by using a sample of 10 randomly selected words.Which of the following methods should result in a simple random sample of 10 words from the Address?

In a recent study, it was reported that the proportion of employees who miss work on Fridays is 0.15, and that the standard deviation of the sample proportion is .However, the report did not indicate the sample size n.What was the sample size, assuming the Central Limit Theorem holds in this case?

Why Study Statistics

An Introduction to Statistics and Statistical Inference

Tables and Graphs for Summarizing Data

Numerical Summary Measures

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Confidence Intervals Based on a Single Sample

Hypothesis Tests Based on a Single Sample

Confidence Intervals and Hypothesis Tests Based on Two Samples or Treatments

The Analysis of Variance

Correlation and Linear Regression

Categorical Data and Frequency Tables

Nonparametric Statistics

Filters

Exam 8: Sampling Distributions

We wish to record the results from two six-sided die rolls.How many unique outcomes are possible?

A heavily right-skewed population has a mean of 28 and a standard deviation of 2.What is the probability that a random sample of 5 from this population will average less than 27?

In the normal process of simple random sampling (SRS), samples are almost always drawn without replacement.Why is this a problem for the assumptions involved with a true SRS?

If the population proportion is 0.38, what is if we calculate using 20 samples?

The standard error of a statistic used as an estimator of a population parameter is:

A sample of 82 mice is observed from birth until they are one year old.The total amount of growth experienced by each mouse is recorded.The median amount of growth of these mice is 4.5 cm.In this example, 4.5 cm is a:

An exponential population has parameter λ = 0.012 (hence, μ= 83.33, σ2= 6944.44).What is the probability that a random sample of 41 from this population will average between 81 and 84?

Suppose you are interested in determining the average word length in Lincoln's Gettysburg Address.You decide to estimate this average word length by using a sample of 10 randomly selected words.Which of the following methods should result in a simple random sample of 10 words from the Address?

In a recent study, it was reported that the proportion of employees who miss work on Fridays is 0.15, and that the standard deviation of the sample proportion is .However, the report did not indicate the sample size n.What was the sample size, assuming the Central Limit Theorem holds in this case?

Why Study Statistics

An Introduction to Statistics and Statistical Inference

Tables and Graphs for Summarizing Data

Numerical Summary Measures

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Confidence Intervals Based on a Single Sample

Hypothesis Tests Based on a Single Sample

Confidence Intervals and Hypothesis Tests Based on Two Samples or Treatments

The Analysis of Variance

Correlation and Linear Regression

Categorical Data and Frequency Tables

Nonparametric Statistics

Filters