Question 1

How might the shapes of a population distribution and a sampling distribution look the same? How might they look different?

Accepted Answer

A population distribution and sampling d

Question 2

Use the following information to answer questions (1) - (4). A sprint duathlon consists of a 5 km run, a 20 km
bike ride, followed by another 5 km run. The mean finish time of all participants in a recent large duathlon was
-What is the standard error for the mean finish time of 30 randomly selected participants in the 40-44 age group? Round to the nearest thousandth.

Accepted Answer

A) 0.046 
B) 0.300 
C) 0.250 
D) 0.055 
A) 0.046 
B) 0.300 
C) 0.250 
D) 0.055

Question 3

Choose the statement that describes a situation where a confidence interval and a hypothesis test would yield the same results.

Accepted Answer

A) When the null hypothesis contains a population parameter that is equal to zero. 
B) When the alternative hypothesis is two-tailed. 
C) Both (a) and (b) 
D) Neither (a) nor (b).The confidence interval cannot yield results that are the same as the hypothesis test. 
A) When the null hypothesis contains a population parameter that is equal to zero. 
B) When the alternative hypothesis is two-tailed. 
C) Both (a) and (b) 
D) Neither (a) nor (b).The confidence interval cannot yield results that are the same as the hypothesis test.

Question 4

Use the following information to answer questions (8) - (10). Suppose that the mean Systolic blood pressure for
adults age 50-54 is 125 mmHg with a standard deviation of 5 mmHg. It is known that Systolic blood pressure is not
Normally distributed. Suppose a sample of 25 adult Systolic blood pressure measurements is taken from the
population.
-What is the approximate standard error for the sampling distribution of mean blood pressures? Round to the nearest hundredth.

Accepted Answer

A) 0.20 
B) 17.00 
C) 5.00 
D) 1.00 
A) 0.20 
B) 17.00 
C) 5.00 
D) 1.00

Question 5

Use the following information to answer questions (1) - (4). A sprint duathlon consists of a 5 km run, a 20 km
bike ride, followed by another 5 km run. The mean finish time of all participants in a recent large duathlon was
-Suppose we were to make a histogram of the finishing times of the 30 participants in the 40-44 age group. Would the histogram be a display of the population distribution, the distribution of a sample, or the sampling distribution of means?

Accepted Answer

A) population distribution 
B) distribution of a sample 
C) sampling distribution of means 
D) normal distribution 
A) population distribution 
B) distribution of a sample 
C) sampling distribution of means 
D) normal distribution

Question 6

Which of the following is a true statement about the Central Limit Theorem for sample means?

Accepted Answer

A) If the sample size is large, it doesn't matter what the distribution of the population it was drawn from is, the normal distribution can still be used to perform statistical inference. 
B) If conditions are met, the mean of the sampling distribution is equal to the population mean. 
C) The Central Limit Theorem helps us find probabilities for sample means when those means are based on a random sample from a population. 
D) All of the statements are true about the Central Limit Theorem for sample means. 
A) If the sample size is large, it doesn't matter what the distribution of the population it was drawn from is, the normal distribution can still be used to perform statistical inference. 
B) If conditions are met, the mean of the sampling distribution is equal to the population mean. 
C) The Central Limit Theorem helps us find probabilities for sample means when those means are based on a random sample from a population. 
D) All of the statements are true about the Central Limit Theorem for sample means.

Question 7

Use the following information to answer questions (11)-(13). According to the website www.costofwedding.com,
the average cost of flowers for a wedding is $698. Recently, in a random sample of 40 weddings in the U. S. it
was found that the average cost of the flowers was $734, with a standard deviation of $102. On the basis of this, a
95% confidence interval for the mean cost of flowers for a wedding is $701 to $767.
-Which of the following statements is true about the t-distribution?

Accepted Answer

A) For small sample sizes, the t-distribution has the same properties of the normal curve. 
B) For large sample sizes, the t-distribution has the same properties of the normal curve. 
C) Like the Normal distribution, the t-distribution is symmetric for small n. 
D) Since population standard deviation is usually unknown, the standard error uses the sample standard deviation to estimate population standard deviation. 
A) For small sample sizes, the t-distribution has the same properties of the normal curve. 
B) For large sample sizes, the t-distribution has the same properties of the normal curve. 
C) Like the Normal distribution, the t-distribution is symmetric for small n. 
D) Since population standard deviation is usually unknown, the standard error uses the sample standard deviation to estimate population standard deviation.

Question 8

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

Accepted Answer

A) The sample mean will always equal the population mean. 
B) On average, the sample mean is the same as the population mean. 
C) The standard deviation of the sampling distribution (also called the standard error) and the population standard deviation are equal. 
D) We cannot say that the sample mean is unbiased. 
A) The sample mean will always equal the population mean. 
B) On average, the sample mean is the same as the population mean. 
C) The standard deviation of the sampling distribution (also called the standard error) and the population standard deviation are equal. 
D) We cannot say that the sample mean is unbiased.

Question 9

Use the following information to answer questions (1) - (4). A sprint duathlon consists of a 5 km run, a 20 km
bike ride, followed by another 5 km run. The mean finish time of all male participants in a recent large duathlon
was 1.54 hours with a standard deviation of 0.22 hours. The distribution of finish times for males is right-skewed.
Suppose that a sample of 30 randomly selected male participants is selected.
-Calculate the standard error for the mean finish time of 30 randomly selected male participants. Show all your work and round to the nearest thousandth.

Accepted Answer

The answer of Use the following information to answer questions...

Question 10

Use the following information to answer questions (12)-(15). Many couples believe that it is getting too expensive to host an "average" wedding in the United States. According to a statistics study in the U.S., the average cost of a wedding in the U.S. in 2014 was $25,200. Recently, in a random sample of 35 weddings in the U.S. it was found that the average cost of a wedding was $24,224 with a standard deviation of $2,210.
-a. Find the critical z value for the given level of confidence and multiply by the standard error using the formula  
b. Find the critical t value for the given level of confidence and multiply by the standard error using the formula  
c. Find the critical z value for the given level of confidence and multiply by the standard error using the formula  
d. Find the critical t value for the given level of confidence and multiply by the standard error using the formula

Accepted Answer

The answer of Use the following information to answer questions...

Question 11

Compare the normal distribution and the t- distribution. How are they similar? How are they different?

Accepted Answer

Both distributions are symmetrical and u

Question 12

A sociologist wants to know whether there is a difference in the mean number of times that men and women in the U. S. check their Smartphone during the day. Test the hypothesis that the mean number of times that men and women in the U. S. check their Smartphone during the day is different. Following are the summary statistics:   Assume that all conditions for testing have been met. Be sure to report the null and alternative hypothesis, test statistic, p-value, your decision regarding the null hypothesis, and your conclusion about the original claim. Round all values to the nearest thousandth.

Accepted Answer

The answer of A sociologist wants to know whether there...

Question 13

A researcher wants to know if mood is affected by music. She conducts a test on a sample of 4 randomly selected adults and measures mood rating before and after being exposed to classic rock music. Test the hypothesis that mood rating decreased after being exposed to classic rock music. Following are the mood ratings for the four participants: 
 
Assume that all conditions for testing have been met. Report the null and alternative hypothesis and P- value. At the 5% significance level, state your decision regarding the null hypothesis and your conclusion about the original claim. Round all values to the nearest thousandth.

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 14

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

Accepted Answer

A) The sample mean will always equal the population mean. 
B) The standard deviation of the sampling distribution (also called the standard error) and the population standard deviation are equal. 
C) On average, the sample mean is the same as the population mean. 
D) We cannot say that the sample mean is unbiased. 
A) The sample mean will always equal the population mean. 
B) The standard deviation of the sampling distribution (also called the standard error) and the population standard deviation are equal. 
C) On average, the sample mean is the same as the population mean. 
D) We cannot say that the sample mean is unbiased.

Question 15

[Differentiate between dependent and independent samples] State whether the situation has dependent or independent samples. A researcher wants to know if reaction time is affected by body type of the vehicle being driven. He measures the reaction time of 40 drivers while they drive a compact car then he measures the reaction time while they drive an SUV.

Accepted Answer

The sample

Question 16

Use the following information to answer questions (1) - (5). Feature movie lengths (in hours) were measured for all movies shown in the past year in the U.S. The mean length of all feature length movies shown was 1.80 hours with a standard deviation of 0.15 hours. Suppose the length of a random sample of 20 movies was recorded from all movies released this year. The mean length of the feature length movies was found to be 1.72 hours with a standard
deviation of 0.18 hours.
-What is the standard error for the estimated mean feature length movie time of the 20 randomly selected movies? Round to the nearest thousandth.

Accepted Answer

A) 0.356 
B) 0.040 
C) 0.055 
D) 0.034 
A) 0.356 
B) 0.040 
C) 0.055 
D) 0.034

Question 17

Use the following information to answer questions (1) - (4). A sprint duathlon consists of a 5 km run, a 20 km
bike ride, followed by another 5 km run. The mean finish time of all male participants in a recent large duathlon
was 1.54 hours with a standard deviation of 0.22 hours. The distribution of finish times for males is right-skewed.
Suppose that a sample of 30 randomly selected male participants is selected.
-What is the expected finish time for a male participant in the sample of 30? Will the expected mean finish time be the same for any sample of 30 males drawn from the population? Explain.

Accepted Answer

The sample mean can vary from

How might the shapes of a population distribution and a sampling distribution look the same? How might they look different?

Choose the statement that describes a situation where a confidence interval and a hypothesis test would yield the same results.

Which of the following is a true statement about the Central Limit Theorem for sample means?

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

Compare the normal distribution and the t- distribution. How are they similar? How are they different?

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

Introduction to Data

Picturing Variation With Graphs

Numerical Summaries of Center and Variation

Regression Analysis: Exploring Associations Between Variables

Modeling Variation With Probability

Modeling Random Events: the Normal and Binomial Models

Survey Sampling and Inference

Hypothesis Testing for Population Proportions

Associations Between Categorical Variables

Multiple Comparisons and Analysis of Variance

Experimental Design: Controlling Variation

Inference Without Normality

Inference for Regression

Filters

Exam 9: Inferring Population Means

How might the shapes of a population distribution and a sampling distribution look the same? How might they look different?

Choose the statement that describes a situation where a confidence interval and a hypothesis test would yield the same results.

Which of the following is a true statement about the Central Limit Theorem for sample means?

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

Compare the normal distribution and the t- distribution. How are they similar? How are they different?

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

Introduction to Data

Picturing Variation With Graphs

Numerical Summaries of Center and Variation

Regression Analysis: Exploring Associations Between Variables

Modeling Variation With Probability

Modeling Random Events: the Normal and Binomial Models

Survey Sampling and Inference

Hypothesis Testing for Population Proportions

Associations Between Categorical Variables

Multiple Comparisons and Analysis of Variance

Experimental Design: Controlling Variation

Inference Without Normality

Inference for Regression

Filters