QUESTION 1
·
1/1 POINTS
The partners at an investment firm want to know which of their two star financial
planners, Brayden or Zoe, produced a higher mean rate of return last quarter for their
clients. The partners reviewed last quarter’s rates of return for random samples of
clients who were managed by Brayden or Zoe. The mean rate of return for the sample
of 30 of Brayden’s clients was 3.54% with a standard deviation of 0.92%. The mean
rate of return for a sample of 30 of Zoe’s clients was 3.87% with a standard deviation
of 2.08%. Let μ1 be the population mean rate of return for Brayden’s clients and μ2 be
the population rate of return for Zoe’s clients. The partners assume the population
standard deviations are not equal and, since Zoe's mean is higher, test the alternative
hypothesis Ha:μ1−μ2<0. If the p-value of the hypothesis test is greater
than 0.10 and the significance level is α=0.05, what conclusion could be made about
the population mean rate of return for Brayden and Zoe? Identify all of the appropriate
conclusions to the hypothesis test below.
That is correct!
•
Reject the null hypothesis.
•
•
Fail to reject the null hypothesis.
•
•
The conclusion of the hypothesis test is that there is sufficient evidence to suggest that
the population mean rate of return for Zoe is greater than the population mean rate of
return for Brayden.
•
,•
The conclusion of the hypothesis test is that there is insufficient evidence to suggest
that the population mean rate of return for Zoe is greater than the population mean rate
of return for Brayden.
•
Answer Explanation
Correct answer:
Fail to reject the null hypothesis.
The conclusion of the hypothesis test is that there is insufficient evidence to suggest
that the population mean rate of return for Zoe is greater than the population mean rate
of return for Brayden.
Compare the p-value that is greater than 0.10 to α=0.05. Since the p-value is greater
than α, fail to reject H0. Therefore, there is insufficient evidence at the α=0.05 level of
significance that the population mean rate of return for Zoe is greater than
the population mean rate of return for Brayden.
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 2
·
1/1 POINTS
To test a drug intended to increase memory capacity, 80 subjects were randomly given
a pill that either contained a drug or was a placebo. After ten minutes, the subjects were
asked to look at a poster with pictures of 20 common objects for five minutes. After
waiting ten minutes, the subjects were asked to list as many of the objects as they could
recall. For the 44 subjects who took the drug, 75% were able to list at least half of the
objects. For the 36 subjects who took the placebo, 50% were able to list at least half
, of the objects. Let p1 be the population proportion of subjects who took the drug and
were able to list at least half of the objects, and let p2 be the population proportion of
subjects who took the placebo and were able to list at least half of the objects. To test
the alternative hypothesis Ha:p1−p2≠0, what are the critical values? Use the level of
significance α=0.05 and round your answers to two decimal places.
zz0.10 zz0.05 zz0.025 zz0.01 zz0.005
1.282 1.645 1.960 2.326 2.576
That is correct!
$$z=±1.96
Answer Explanation
Correct answers:
• $z=\pm1.96$z=±1.96
Notice that this is a two-tailed test. The z-values that correspond to the level of
significance are −1.96 and 1.96.
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 3
·
1/1 POINTS
A doctor keeps track of the number of babies she delivers in each season. She expects
that the distribution will be uniform (the same number of babies in each season). The
·
1/1 POINTS
The partners at an investment firm want to know which of their two star financial
planners, Brayden or Zoe, produced a higher mean rate of return last quarter for their
clients. The partners reviewed last quarter’s rates of return for random samples of
clients who were managed by Brayden or Zoe. The mean rate of return for the sample
of 30 of Brayden’s clients was 3.54% with a standard deviation of 0.92%. The mean
rate of return for a sample of 30 of Zoe’s clients was 3.87% with a standard deviation
of 2.08%. Let μ1 be the population mean rate of return for Brayden’s clients and μ2 be
the population rate of return for Zoe’s clients. The partners assume the population
standard deviations are not equal and, since Zoe's mean is higher, test the alternative
hypothesis Ha:μ1−μ2<0. If the p-value of the hypothesis test is greater
than 0.10 and the significance level is α=0.05, what conclusion could be made about
the population mean rate of return for Brayden and Zoe? Identify all of the appropriate
conclusions to the hypothesis test below.
That is correct!
•
Reject the null hypothesis.
•
•
Fail to reject the null hypothesis.
•
•
The conclusion of the hypothesis test is that there is sufficient evidence to suggest that
the population mean rate of return for Zoe is greater than the population mean rate of
return for Brayden.
•
,•
The conclusion of the hypothesis test is that there is insufficient evidence to suggest
that the population mean rate of return for Zoe is greater than the population mean rate
of return for Brayden.
•
Answer Explanation
Correct answer:
Fail to reject the null hypothesis.
The conclusion of the hypothesis test is that there is insufficient evidence to suggest
that the population mean rate of return for Zoe is greater than the population mean rate
of return for Brayden.
Compare the p-value that is greater than 0.10 to α=0.05. Since the p-value is greater
than α, fail to reject H0. Therefore, there is insufficient evidence at the α=0.05 level of
significance that the population mean rate of return for Zoe is greater than
the population mean rate of return for Brayden.
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 2
·
1/1 POINTS
To test a drug intended to increase memory capacity, 80 subjects were randomly given
a pill that either contained a drug or was a placebo. After ten minutes, the subjects were
asked to look at a poster with pictures of 20 common objects for five minutes. After
waiting ten minutes, the subjects were asked to list as many of the objects as they could
recall. For the 44 subjects who took the drug, 75% were able to list at least half of the
objects. For the 36 subjects who took the placebo, 50% were able to list at least half
, of the objects. Let p1 be the population proportion of subjects who took the drug and
were able to list at least half of the objects, and let p2 be the population proportion of
subjects who took the placebo and were able to list at least half of the objects. To test
the alternative hypothesis Ha:p1−p2≠0, what are the critical values? Use the level of
significance α=0.05 and round your answers to two decimal places.
zz0.10 zz0.05 zz0.025 zz0.01 zz0.005
1.282 1.645 1.960 2.326 2.576
That is correct!
$$z=±1.96
Answer Explanation
Correct answers:
• $z=\pm1.96$z=±1.96
Notice that this is a two-tailed test. The z-values that correspond to the level of
significance are −1.96 and 1.96.
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 3
·
1/1 POINTS
A doctor keeps track of the number of babies she delivers in each season. She expects
that the distribution will be uniform (the same number of babies in each season). The
