The t test for the difference between the means of 2 independent populations assumes that the
respective
a. sample sizes are equal.
b. sample variances are equal.
c. populations are approximately normal.
d. All of these. - Answers c
In testing for differences between the means of two independent populations, the null hypothesis is
a. H0: 1 - 2 = 2.
b. H0: 1 - 2 = 0.
c. H0: 1 - 2 > 0.
d. H0: 1 - 2 < 2. - Answers b
The sample size in each independent sample must be the same if we are to test for differences
between the means of two independent populations.
True
False - Answers False
A statistics professor wanted to test whether the grades on a statistics test were the same for upper
and lower classmen. The professor took a random sample of size 10 from each, conducted a test and
found out that the variances were equal. For this situation, the professor should use a t test with
related samples.
True
False - Answers False
Are Japanese managers more motivated than American managers? A randomly selected group of
each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures
motivation for upward mobility. The SSATL scores are summarized below.
Referring to Table 10-1, judging from the way the data were collected, which test would likely be
most appropriate to employ?
a. Paired t test
b. Pooled-variance t test for the difference between two means
c. F test for the ratio of two variances
d. Z test for the difference between two proportions - Answers b
Are Japanese managers more motivated than American managers? A randomly selected group of
each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures
motivation for upward mobility. The SSATL scores are summarized below.
Referring to Table 10-1, give the null and alternative hypotheses to determine if the mean SSATL
score of Japanese managers differs from the mean SSATL score of American managers.
a. H0: A - J≥0 versus H1: A - J < 0
b. H0: A - J ≤ 0 versus H1: A - J > 0
c. H0: A - J = 0 versus H1: A - J ≠0
d. H0 : A - J = 0 versus H1: A - J≠0 - Answers c.
Are Japanese managers more motivated than American managers? A randomly selected group of
each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures
motivation for upward mobility. The SSATL scores are summarized below.
, Referring to Table 10-1, what is the value of the test statistic?
Selected Answer:
a. -14.08
b. -11.8092
c. -1.9677
d. 96.4471 - Answers b
Are Japanese managers more motivated than American managers? A randomly selected group of
each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures
motivation for upward mobility. The SSATL scores are summarized below.
Referring to Table 10-1, find the p-value if we assume that the alternative hypothesis was a two-tail
test.
a. Smaller than 0.01
b. Between 0.01 and 0.05
c. Between 0.05 and 0.10
d. Greater than 0.10 - Answers a
A real estate company is interested in testing whether the mean time that families in Gotham have
been living in their current homes is less than families in Metropolis. Assume that the two population
variances are equal. A random sample of 100 families from Gotham and a random sample of 150
families in Metropolis yield the following data on length of residence in current homes.
Referring to Table 10-3, which of the following represents the relevant hypotheses tested by the real
estate company?
a. H0:μG - M≥0 versus H1:μG - M < 0
b. H0:μG - M≤0 versus H1:μG - M > 0
c. H0:μG - M = 0 versus H1:μG - M≠0
d. H0 :x̄ G - M≥0 versus H1 :x̄G - M < 0 - Answers a
In what type of test is the variable of interest the difference between the values of the observations
rather than the observations themselves?
a. A test for the equality of variances from 2 independent populations
b. A test for the difference between the means of 2 related populations
c. A test for the difference between the means of 2 independent populations
d. All of these. - Answers b
In testing for differences between the means of two related populations, the null hypothesis is
a. H0: D = 2.
b. H0: D = 0.
c. H0: D < 0.
d. H0: D > 0. - Answers b
A researcher is curious about the effect of sleep on students' test performances. He chooses 60
students and gives each two tests: one given after two hours' sleep and one after eight hours' sleep.
The test the researcher should use would be a related samples test.
True
False - Answers True
A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging.
In order to determine if his suspicion is correct, he contacts a second supplier and asks for the prices