Question 1
Does secondhand smoke increase the risk of a low birthweight? A baby is considered have low birthweight if he/she weighs less than 5.5 pounds at birth. According to the National Center of Health Statistics, about 7.8% of all babies born in the U.S. are categorized as low birthweight.
Suspecting that the national percentage is higher than 7.8%, researchers randomly select 1,200 babies whose mothers had extensive exposure to secondhand smoke during pregnancy and find that 10.4% of the sampled babies are categorized as low birth weight.
Let p be the proportion of all babies in the United States who are categorized as low birth weight. What are the appropriate null and alternative hypotheses for this research question?

H _{0}: p = 0.078
H _{a}: p ≠ 0.078

H_{0}: p = 0.078
H_{a}: p > 0.078

H_{0}: p = 0.104
H_{a}: p ≠ 0.104

H_{0}: μ = 0.078
H_{a}: μ > 0.078
Question 2
Select one answer.
10 points
A manufacturer of tshirts marks a shirt as “irregular” when it has defects such as crooked seams, stains, rips, or holes. A small number of irregular tshirts are expected as part of the manufacturing process, but if more than 8% of the tshirts manufactured at a plant are classified as irregular, the manager has to do an investigation to try to find the source of the increased mistakes in the manufacturing process.
In order to test whether his plant is making a higher than expected number of irregular tshirts, the manager of a plant randomly selects 100 tshirts and finds that 12 are irregular.
He plans to test the hypotheses: H_{0}, P = 0.08, versus H_{a}, p > 0.08 (where p is the true proportion of irregular tshirts). What is the test statistic?
 Z = −1.47
 Z = 5
 Z = 1.47
 Z = −1.23
Question 3
Select one answer.
10 points
A researcher wants to find out if U.S. adults still support the death penalty at a proportion of 0.64 (as it was in 2003). This graph indicates the sampling distribution for the proportion of supporters in random samples of 25 adults. The standard deviation is approximately 0.10.
What is the approximate test statistic for p̂ = 0.84?
 −2
 −1
 0
 1
 2
Question 4
Select one answer.
10 points
The proportion of college football players who have had at least one concussion is estimated to be 34% in the United States. We wanted to know if football players at our university were less likely to have suffered a concussion, so we surveyed a random sample of 100 past and present football players at our university. Is this survey valid or not valid for testing the hypothesis that the proportion of college football players at our university with at least one concussion is less than the national average?
 Valid
 Not valid
Question 5
Select one answer.
10 points
According to a U.S. news poll, 38% of students in the class of 2013 had done an internship during their time as an undergraduate student. Dana is interested in finding out whether students at her university had an internship rate that was higher than the national average. She obtained a list of 25 randomly selected students from the population of all students at her university by requesting this information from the university’s institutional research office. She collected the responses and calculated that the proportion for her university was 43%.
Which one of the following statements about the ztest is correct?
 It is not safe to use the ztest for p, since the sample is not a random sample from the entire population (or cannot be considered as one).
 It is not safe to use the ztest for p, since n * p_{o} is not large enough.
 It is not safe to use the ztest for p, since n * (1 − p_{o}) is not large enough.
 It is safe to use the ztest for p.
Question 6
Select all that apply.
10 points
A national poll by the Institute for College Access and Success showed that in 69% of college graduates from public and nonprofit colleges in 2013 had student loan debt. Dr. Blackman wanted to find out if her public nonprofit university had a lower proportion of students who graduated with student loan debt in 2013.
For this survey, the null hypothesis was that the proportion of students with graduated with student loan debt equals 69% and the alternative hypothesis is that the proportion with student loan debt does not equal 69%. The significance level for this test was 0.05.
The results of the hypothesis test of the new survey showed a pvalue of 0.039.
Which of the following statements is correct? Check all that apply.
 The results were statistically significant.
 The results were not statistically significant.
 The null hypothesis should be rejected.
 The null hypothesis should be accepted.
 The null hypothesis cannot be rejected.
Question 1
Does secondhand smoke increase the risk of a low birthweight? A baby is considered have low birthweight if he/she weighs less than 5.5 pounds at birth. According to the National Center of Health Statistics, about 7.8% of all babies born in the U.S. are categorized as low birthweight.
Suspecting that the national percentage is higher than 7.8%, researchers randomly select 1,200 babies whose mothers had extensive exposure to secondhand smoke during pregnancy and find that 10.4% of the sampled babies are categorized as low birth weight.
Let p be the proportion of all babies in the United States who are categorized as low birth weight. What are the appropriate null and alternative hypotheses for this research question?

H _{0}: p = 0.078
H _{a}: p ≠ 0.078

H_{0}: p = 0.078
H_{a}: p > 0.078

H_{0}: p = 0.104
H_{a}: p ≠ 0.104

H_{0}: μ = 0.078
H_{a}: μ > 0.078
Question 2
Select one answer.
10 points
A manufacturer of tshirts marks a shirt as “irregular” when it has defects such as crooked seams, stains, rips, or holes. A small number of irregular tshirts are expected as part of the manufacturing process, but if more than 8% of the tshirts manufactured at a plant are classified as irregular, the manager has to do an investigation to try to find the source of the increased mistakes in the manufacturing process.
In order to test whether his plant is making a higher than expected number of irregular tshirts, the manager of a plant randomly selects 100 tshirts and finds that 12 are irregular.
He plans to test the hypotheses: H_{0}, P = 0.08, versus H_{a}, p > 0.08 (where p is the true proportion of irregular tshirts). What is the test statistic?
 Z = −1.47
 Z = 5
 Z = 1.47
 Z = −1.23
Question 3
Select one answer.
10 points
A researcher wants to find out if U.S. adults still support the death penalty at a proportion of 0.64 (as it was in 2003). This graph indicates the sampling distribution for the proportion of supporters in random samples of 25 adults. The standard deviation is approximately 0.10.
What is the approximate test statistic for p̂ = 0.84?
 −2
 −1
 0
 1
 2
Question 4
Select one answer.
10 points
The proportion of college football players who have had at least one concussion is estimated to be 34% in the United States. We wanted to know if football players at our university were less likely to have suffered a concussion, so we surveyed a random sample of 100 past and present football players at our university. Is this survey valid or not valid for testing the hypothesis that the proportion of college football players at our university with at least one concussion is less than the national average?
 Valid
 Not valid
Question 5
Select one answer.
10 points
According to a U.S. news poll, 38% of students in the class of 2013 had done an internship during their time as an undergraduate student. Dana is interested in finding out whether students at her university had an internship rate that was higher than the national average. She obtained a list of 25 randomly selected students from the population of all students at her university by requesting this information from the university’s institutional research office. She collected the responses and calculated that the proportion for her university was 43%.
Which one of the following statements about the ztest is correct?
 It is not safe to use the ztest for p, since the sample is not a random sample from the entire population (or cannot be considered as one).
 It is not safe to use the ztest for p, since n * p_{o} is not large enough.
 It is not safe to use the ztest for p, since n * (1 − p_{o}) is not large enough.
 It is safe to use the ztest for p.
Question 6
Select all that apply.
10 points
A national poll by the Institute for College Access and Success showed that in 69% of college graduates from public and nonprofit colleges in 2013 had student loan debt. Dr. Blackman wanted to find out if her public nonprofit university had a lower proportion of students who graduated with student loan debt in 2013.
For this survey, the null hypothesis was that the proportion of students with graduated with student loan debt equals 69% and the alternative hypothesis is that the proportion with student loan debt does not equal 69%. The significance level for this test was 0.05.
The results of the hypothesis test of the new survey showed a pvalue of 0.039.
Which of the following statements is correct? Check all that apply.
 The results were statistically significant.
 The results were not statistically significant.
 The null hypothesis should be rejected.
 The null hypothesis should be accepted.
 The null hypothesis cannot be rejected.
Question 1
Does secondhand smoke increase the risk of a low birthweight? A baby is considered have low birthweight if he/she weighs less than 5.5 pounds at birth. According to the National Center of Health Statistics, about 7.8% of all babies born in the U.S. are categorized as low birthweight.
Suspecting that the national percentage is higher than 7.8%, researchers randomly select 1,200 babies whose mothers had extensive exposure to secondhand smoke during pregnancy and find that 10.4% of the sampled babies are categorized as low birth weight.
Let p be the proportion of all babies in the United States who are categorized as low birth weight. What are the appropriate null and alternative hypotheses for this research question?

H _{0}: p = 0.078
H _{a}: p ≠ 0.078

H_{0}: p = 0.078
H_{a}: p > 0.078

H_{0}: p = 0.104
H_{a}: p ≠ 0.104

H_{0}: μ = 0.078
H_{a}: μ > 0.078
Question 2
Select one answer.
10 points
A manufacturer of tshirts marks a shirt as “irregular” when it has defects such as crooked seams, stains, rips, or holes. A small number of irregular tshirts are expected as part of the manufacturing process, but if more than 8% of the tshirts manufactured at a plant are classified as irregular, the manager has to do an investigation to try to find the source of the increased mistakes in the manufacturing process.
In order to test whether his plant is making a higher than expected number of irregular tshirts, the manager of a plant randomly selects 100 tshirts and finds that 12 are irregular.
He plans to test the hypotheses: H_{0}, P = 0.08, versus H_{a}, p > 0.08 (where p is the true proportion of irregular tshirts). What is the test statistic?
 Z = −1.47
 Z = 5
 Z = 1.47
 Z = −1.23
Question 3
Select one answer.
10 points
A researcher wants to find out if U.S. adults still support the death penalty at a proportion of 0.64 (as it was in 2003). This graph indicates the sampling distribution for the proportion of supporters in random samples of 25 adults. The standard deviation is approximately 0.10.
What is the approximate test statistic for p̂ = 0.84?
 −2
 −1
 0
 1
 2
Question 4
Select one answer.
10 points
The proportion of college football players who have had at least one concussion is estimated to be 34% in the United States. We wanted to know if football players at our university were less likely to have suffered a concussion, so we surveyed a random sample of 100 past and present football players at our university. Is this survey valid or not valid for testing the hypothesis that the proportion of college football players at our university with at least one concussion is less than the national average?
 Valid
 Not valid
Question 5
Select one answer.
10 points
According to a U.S. news poll, 38% of students in the class of 2013 had done an internship during their time as an undergraduate student. Dana is interested in finding out whether students at her university had an internship rate that was higher than the national average. She obtained a list of 25 randomly selected students from the population of all students at her university by requesting this information from the university’s institutional research office. She collected the responses and calculated that the proportion for her university was 43%.
Which one of the following statements about the ztest is correct?
 It is not safe to use the ztest for p, since the sample is not a random sample from the entire population (or cannot be considered as one).
 It is not safe to use the ztest for p, since n * p_{o} is not large enough.
 It is not safe to use the ztest for p, since n * (1 − p_{o}) is not large enough.
 It is safe to use the ztest for p.
Question 6
Select all that apply.
10 points
A national poll by the Institute for College Access and Success showed that in 69% of college graduates from public and nonprofit colleges in 2013 had student loan debt. Dr. Blackman wanted to find out if her public nonprofit university had a lower proportion of students who graduated with student loan debt in 2013.
For this survey, the null hypothesis was that the proportion of students with graduated with student loan debt equals 69% and the alternative hypothesis is that the proportion with student loan debt does not equal 69%. The significance level for this test was 0.05.
The results of the hypothesis test of the new survey showed a pvalue of 0.039.
Which of the following statements is correct? Check all that apply.
 The results were statistically significant.
 The results were not statistically significant.
 The null hypothesis should be rejected.
 The null hypothesis should be accepted.
 The null hypothesis cannot be rejected.
Question 1
Question 1
Does secondhand smoke increase the risk of a low birthweight? A baby is considered have low birthweight if he/she weighs less than 5.5 pounds at birth. According to the National Center of Health Statistics, about 7.8% of all babies born in the U.S. are categorized as low birthweight.
Does secondhand smoke increase the risk of a low birthweight? A baby is considered have low birthweight if he/she weighs less than 5.5 pounds at birth. According to the National Center of Health Statistics, about 7.8% of all babies born in the U.S. are categorized as low birthweight.
Suspecting that the national percentage is higher than 7.8%, researchers randomly select 1,200 babies whose mothers had extensive exposure to secondhand smoke during pregnancy and find that 10.4% of the sampled babies are categorized as low birth weight.
Suspecting that the national percentage is higher than 7.8%, researchers randomly select 1,200 babies whose mothers had extensive exposure to secondhand smoke during pregnancy and find that 10.4% of the sampled babies are categorized as low birth weight.
Let p be the proportion of all babies in the United States who are categorized as low birth weight. What are the appropriate null and alternative hypotheses for this research question?
Let p be the proportion of all babies in the United States who are categorized as low birth weight. What are the appropriate null and alternative hypotheses for this research question?

H _{0}: p = 0.078
H _{a}: p ≠ 0.078

H_{0}: p = 0.078
H_{a}: p > 0.078

H_{0}: p = 0.104
H_{a}: p ≠ 0.104

H_{0}: μ = 0.078
H_{a}: μ > 0.078
H _{0}: p = 0.078
H _{a}: p ≠ 0.078
H _{0}: p = 0.078
H _{0}: p = 0.078_{0}
H _{a}: p ≠ 0.078
H _{a}: p ≠ 0.078_{a}
H_{0}: p = 0.078
H_{a}: p > 0.078
H_{0}: p = 0.078
H_{0}: p = 0.078_{0}
H_{a}: p > 0.078
H_{a}: p > 0.078_{a}
H_{0}: p = 0.104
H_{a}: p ≠ 0.104
H_{0}: p = 0.104
H_{0}: p = 0.104_{0}
H_{a}: p ≠ 0.104
H_{a}: p ≠ 0.104_{a}
H_{0}: μ = 0.078
H_{a}: μ > 0.078
H_{0}: μ = 0.078
H_{0}: μ = 0.078_{0}
H_{a}: μ > 0.078
H_{a}: μ > 0.078_{a}
Question 2
Question 2
Select one answer.
Select one answer.
10 points
10 points
A manufacturer of tshirts marks a shirt as “irregular” when it has defects such as crooked seams, stains, rips, or holes. A small number of irregular tshirts are expected as part of the manufacturing process, but if more than 8% of the tshirts manufactured at a plant are classified as irregular, the manager has to do an investigation to try to find the source of the increased mistakes in the manufacturing process.
A manufacturer of tshirts marks a shirt as “irregular” when it has defects such as crooked seams, stains, rips, or holes. A small number of irregular tshirts are expected as part of the manufacturing process, but if more than 8% of the tshirts manufactured at a plant are classified as irregular, the manager has to do an investigation to try to find the source of the increased mistakes in the manufacturing process.
In order to test whether his plant is making a higher than expected number of irregular tshirts, the manager of a plant randomly selects 100 tshirts and finds that 12 are irregular.
In order to test whether his plant is making a higher than expected number of irregular tshirts, the manager of a plant randomly selects 100 tshirts and finds that 12 are irregular.
He plans to test the hypotheses: H_{0}, P = 0.08, versus H_{a}, p > 0.08 (where p is the true proportion of irregular tshirts). What is the test statistic?
He plans to test the hypotheses: H_{0}, P = 0.08, versus H_{a}, p > 0.08 (where p is the true proportion of irregular tshirts). What is the test statistic?_{0}_{a}
 Z = −1.47
 Z = 5
 Z = 1.47
 Z = −1.23
Z = −1.47
Z = 5
Z = 1.47
Z = −1.23
Question 3
Question 3
Select one answer.
Select one answer.
10 points
10 points
A researcher wants to find out if U.S. adults still support the death penalty at a proportion of 0.64 (as it was in 2003). This graph indicates the sampling distribution for the proportion of supporters in random samples of 25 adults. The standard deviation is approximately 0.10.
A researcher wants to find out if U.S. adults still support the death penalty at a proportion of 0.64 (as it was in 2003). This graph indicates the sampling distribution for the proportion of supporters in random samples of 25 adults. The standard deviation is approximately 0.10.
What is the approximate test statistic for p̂ = 0.84?
What is the approximate test statistic for p̂ = 0.84?
 −2
 −1
 0
 1
 2
−2
−1
0
1
2
Question 4
Question 4
Select one answer.
Select one answer.
10 points
10 points
The proportion of college football players who have had at least one concussion is estimated to be 34% in the United States. We wanted to know if football players at our university were less likely to have suffered a concussion, so we surveyed a random sample of 100 past and present football players at our university. Is this survey valid or not valid for testing the hypothesis that the proportion of college football players at our university with at least one concussion is less than the national average?
The proportion of college football players who have had at least one concussion is estimated to be 34% in the United States. We wanted to know if football players at our university were less likely to have suffered a concussion, so we surveyed a random sample of 100 past and present football players at our university. Is this survey valid or not valid for testing the hypothesis that the proportion of college football players at our university with at least one concussion is less than the national average?
 Valid
 Not valid
Valid
Not valid
Question 5
Question 5
Select one answer.
Select one answer.
10 points
10 points
According to a U.S. news poll, 38% of students in the class of 2013 had done an internship during their time as an undergraduate student. Dana is interested in finding out whether students at her university had an internship rate that was higher than the national average. She obtained a list of 25 randomly selected students from the population of all students at her university by requesting this information from the university’s institutional research office. She collected the responses and calculated that the proportion for her university was 43%.
According to a U.S. news poll, 38% of students in the class of 2013 had done an internship during their time as an undergraduate student. Dana is interested in finding out whether students at her university had an internship rate that was higher than the national average. She obtained a list of 25 randomly selected students from the population of all students at her university by requesting this information from the university’s institutional research office. She collected the responses and calculated that the proportion for her university was 43%.
Which one of the following statements about the ztest is correct?
Which one of the following statements about the ztest is correct?
 It is not safe to use the ztest for p, since the sample is not a random sample from the entire population (or cannot be considered as one).
 It is not safe to use the ztest for p, since n * p_{o} is not large enough.
 It is not safe to use the ztest for p, since n * (1 − p_{o}) is not large enough.
 It is safe to use the ztest for p.
It is not safe to use the ztest for p, since the sample is not a random sample from the entire population (or cannot be considered as one).
It is not safe to use the ztest for p, since n * p_{o} is not large enough._{o}
It is not safe to use the ztest for p, since n * (1 − p_{o}) is not large enough._{o}
It is safe to use the ztest for p.
Question 6
Question 6
Select all that apply.
Select all that apply.
10 points
10 points
A national poll by the Institute for College Access and Success showed that in 69% of college graduates from public and nonprofit colleges in 2013 had student loan debt. Dr. Blackman wanted to find out if her public nonprofit university had a lower proportion of students who graduated with student loan debt in 2013.
A national poll by the Institute for College Access and Success showed that in 69% of college graduates from public and nonprofit colleges in 2013 had student loan debt. Dr. Blackman wanted to find out if her public nonprofit university had a lower proportion of students who graduated with student loan debt in 2013.
For this survey, the null hypothesis was that the proportion of students with graduated with student loan debt equals 69% and the alternative hypothesis is that the proportion with student loan debt does not equal 69%. The significance level for this test was 0.05.
For this survey, the null hypothesis was that the proportion of students with graduated with student loan debt equals 69% and the alternative hypothesis is that the proportion with student loan debt does not equal 69%. The significance level for this test was 0.05.
The results of the hypothesis test of the new survey showed a pvalue of 0.039.
The results of the hypothesis test of the new survey showed a pvalue of 0.039.
Which of the following statements is correct? Check all that apply.
Which of the following statements is correct? Check all that apply.
 The results were statistically significant.
 The results were not statistically significant.
 The null hypothesis should be rejected.
 The null hypothesis should be accepted.
 The null hypothesis cannot be rejected.
The results were statistically significant.
The results were not statistically significant.
The null hypothesis should be rejected.
The null hypothesis should be accepted.
The null hypothesis cannot be rejected.