Midterm Exam Prep
1. The National Association of Realtors reported that 26% of home buyers in the state of
Florida are foreigners. When testing the validity of this report, a Type II error would
occur if it was concluded that the proportion of foreign buyers was
Equal to 26% when, in reality, the proportion was not equal to 26%
2. When testing for the population mean when sigma is known and a sample size is
greater than 30, the population must be normally distributed in order for the
conclusions to be reliable.
False
3. A hypothesis is an assumption about a population parameter such as a mean or a
proportion.
True
4. A hypothesis is an assumption about a population parameter such as a mean or a
proportion.
True
5. Historically, voter turnout for political elections in Texas have been reported to be
54%. You have been assigned by a polling company to test the hypothesis that voter
turnout during the most recent election was higher than 54%. You have collected a
random sample of 90 registered voters from this election and found that 54 actually
voted. Assume that the true proportion of voter turnout is 0.67. Calculate the
probability of a Type II error using a = 0.02. Is this answer correct? True = yes, False =
no
True
6. The power curve plots the power values of a hypothesis test over a range of
corresponding sample means.
False
7. The hypothesis statement H: μ = 25 is an example of an alternative hypothesis.
False
8. The null hypothesis is believed to be true unless there is overwhelming evidence to
the contrary.
True
9. The observed level of significance is also known as alpha in a hypothesis test.
False
10. Historically, voter turnout for political elections in Texas have been reported to be
54%. You have been assigned by a polling company to test the hypothesis that voter
turnout during the most recent election was higher than 54%. You have collected a
random sample of 90 registered voters from this election and found that 54 actually
voted. Use the critical value approach to test this hypothesis with a = 0.02.
, Because the p-value > a, we fail to reject the null hypothesis. Therefore, you cannot
conclude that the proportion of voter turnout exceeds 0.54.
False
11. For a one-tail (lower) hypothesis test, if the z- or t-test statistic exceeds the critical
value, we do not reject the null hypothesis.
True
12. A professor would like to test the hypothesis that the average number of minutes
that a student needs to complete a statistics exam is equal to 45 minutes. A Type II
error would occur if the professor concludes that the average exam time is
Equal to 45 minutes when, in reality, the average time is not equal to 45
minutes
13. Historically, voter turnout for political elections in Texas have been reported to be
54%. You have been assigned by a polling company to test the hypothesis that voter
turnout during the most recent election was higher than 54%. You have collected a
random sample of 90 registered voters from this election and found that 54 actually
voted. Use the p-value approach to test this hypothesis with a = 0.02.
Because the p-value > a, we fail to reject the null hypothesis. Therefore, you cannot
conclude that the proportion of voter turnout exceeds 0.54.
False
14. As the true population mean moves away from the hypothesized mean, the power
of the test decreases.
False
15. Because hypothesis testing relies on a sample, we expose ourselves to the risk
that our conclusions about the population will be wrong because of a sampling error.
True
16. Hypothesis testing relies on proof by contradiction where we assume that the
alternative hypothesis is true and attempt to disprove it by finding evidence to the
contrary.
False
17. YouTube would like to test the hypothesis that the average length of an online
video watched by a user is more than 8 minutes. A random sample of 37 people
watched online videos that averaged 8.7 minutes in length. It is believed that the
population standard deviation for the length of online videos is 2.5 minutes. YouTube
would like to set α = 0.02. The test statistic for this hypothesis test would be ________.
, The answer is A
18. Entertainment Software Association would like to test if the average age of
"gamers" (those that routinely play video games) is more than 30 years old. A random
sample of 33 gamers was selected and their ages were recorded. Assume that the
standard deviation for the population of the age of gamers is 4.7 years and the true
population mean for the age of gamers is 31.2 years. Using α = 0.02, beta equals
0.7224
19. The critical sample mean(s) is(are) the sample mean(s) that mark(s) the boundary
of the rejection region.
True
20. A Type II error occurs in hypothesis testing when we _____.
Fail to reject the null hypothesis and the null hypothesis is not true
21. For a two-tail hypothesis test, if the absolute value of the z- or t-test statistic
exceeds the absolute value of the critical value, we reject the null hypothesis.
True
22. The value of β depends on the actual value of μ or p.
True
23. The null hypothesis is also known as the research hypothesis because it represents
the position the researcher wants to establish.
False
24. Once the sample size has been increased to the size of the population, the values
of α and β will approach 1.0.
False
25. For a one-tail (upper) hypothesis test, if the z- or t-test statistic exceeds the critical
value, we do not reject the null hypothesis.
26. The following frequency distribution displays the daily
sales of muffins at Avalon Bakery. What is the probability that between 15 to 21
muffins will be sold tomorrow?
0.26
27. The complement to Event A is defined as all of the
outcomes in the sample space that are not part of Event A
True
1. The National Association of Realtors reported that 26% of home buyers in the state of
Florida are foreigners. When testing the validity of this report, a Type II error would
occur if it was concluded that the proportion of foreign buyers was
Equal to 26% when, in reality, the proportion was not equal to 26%
2. When testing for the population mean when sigma is known and a sample size is
greater than 30, the population must be normally distributed in order for the
conclusions to be reliable.
False
3. A hypothesis is an assumption about a population parameter such as a mean or a
proportion.
True
4. A hypothesis is an assumption about a population parameter such as a mean or a
proportion.
True
5. Historically, voter turnout for political elections in Texas have been reported to be
54%. You have been assigned by a polling company to test the hypothesis that voter
turnout during the most recent election was higher than 54%. You have collected a
random sample of 90 registered voters from this election and found that 54 actually
voted. Assume that the true proportion of voter turnout is 0.67. Calculate the
probability of a Type II error using a = 0.02. Is this answer correct? True = yes, False =
no
True
6. The power curve plots the power values of a hypothesis test over a range of
corresponding sample means.
False
7. The hypothesis statement H: μ = 25 is an example of an alternative hypothesis.
False
8. The null hypothesis is believed to be true unless there is overwhelming evidence to
the contrary.
True
9. The observed level of significance is also known as alpha in a hypothesis test.
False
10. Historically, voter turnout for political elections in Texas have been reported to be
54%. You have been assigned by a polling company to test the hypothesis that voter
turnout during the most recent election was higher than 54%. You have collected a
random sample of 90 registered voters from this election and found that 54 actually
voted. Use the critical value approach to test this hypothesis with a = 0.02.
, Because the p-value > a, we fail to reject the null hypothesis. Therefore, you cannot
conclude that the proportion of voter turnout exceeds 0.54.
False
11. For a one-tail (lower) hypothesis test, if the z- or t-test statistic exceeds the critical
value, we do not reject the null hypothesis.
True
12. A professor would like to test the hypothesis that the average number of minutes
that a student needs to complete a statistics exam is equal to 45 minutes. A Type II
error would occur if the professor concludes that the average exam time is
Equal to 45 minutes when, in reality, the average time is not equal to 45
minutes
13. Historically, voter turnout for political elections in Texas have been reported to be
54%. You have been assigned by a polling company to test the hypothesis that voter
turnout during the most recent election was higher than 54%. You have collected a
random sample of 90 registered voters from this election and found that 54 actually
voted. Use the p-value approach to test this hypothesis with a = 0.02.
Because the p-value > a, we fail to reject the null hypothesis. Therefore, you cannot
conclude that the proportion of voter turnout exceeds 0.54.
False
14. As the true population mean moves away from the hypothesized mean, the power
of the test decreases.
False
15. Because hypothesis testing relies on a sample, we expose ourselves to the risk
that our conclusions about the population will be wrong because of a sampling error.
True
16. Hypothesis testing relies on proof by contradiction where we assume that the
alternative hypothesis is true and attempt to disprove it by finding evidence to the
contrary.
False
17. YouTube would like to test the hypothesis that the average length of an online
video watched by a user is more than 8 minutes. A random sample of 37 people
watched online videos that averaged 8.7 minutes in length. It is believed that the
population standard deviation for the length of online videos is 2.5 minutes. YouTube
would like to set α = 0.02. The test statistic for this hypothesis test would be ________.
, The answer is A
18. Entertainment Software Association would like to test if the average age of
"gamers" (those that routinely play video games) is more than 30 years old. A random
sample of 33 gamers was selected and their ages were recorded. Assume that the
standard deviation for the population of the age of gamers is 4.7 years and the true
population mean for the age of gamers is 31.2 years. Using α = 0.02, beta equals
0.7224
19. The critical sample mean(s) is(are) the sample mean(s) that mark(s) the boundary
of the rejection region.
True
20. A Type II error occurs in hypothesis testing when we _____.
Fail to reject the null hypothesis and the null hypothesis is not true
21. For a two-tail hypothesis test, if the absolute value of the z- or t-test statistic
exceeds the absolute value of the critical value, we reject the null hypothesis.
True
22. The value of β depends on the actual value of μ or p.
True
23. The null hypothesis is also known as the research hypothesis because it represents
the position the researcher wants to establish.
False
24. Once the sample size has been increased to the size of the population, the values
of α and β will approach 1.0.
False
25. For a one-tail (upper) hypothesis test, if the z- or t-test statistic exceeds the critical
value, we do not reject the null hypothesis.
26. The following frequency distribution displays the daily
sales of muffins at Avalon Bakery. What is the probability that between 15 to 21
muffins will be sold tomorrow?
0.26
27. The complement to Event A is defined as all of the
outcomes in the sample space that are not part of Event A
True
