(6 pts) A psychologist who needs two groups of
students for a learning experiment decides to select a random
sample of female college
students and male college students. Before the experiment, the
psychologist administers an IQ test to both groups to determine if
there is a significant difference in their mean IQ scores. The
population standard deviation for this IQ test is know to be
for both female and male populations. If the sample
mean IQ score of the female students is
and the sample mean IQ
score for the male students is , can the psychologist
conclude that there is a significant difference in the mean IQ
score of both groups at ? Let population 1 be
female students and population 2 be male students.
Note that direction is not specified in this
problem, and the population standard deviation is given. See
Chapter 13.
(a) State the hypotheses:
There is Choose: a negative difference a positive difference no difference between the Choose: population proportion population mean sample mean sample proportion IQ score for female students and male students.
The Choose: sample mean sample proportion population proportion population mean IQ score for female students Choose: is less than is different than is greater than is the same as the Choose: sample mean sample proportion population proportion population mean IQ score for male students.
(b) The correct symbol for mean of the sampling
distribution is
A.
B.
C.
D.
E.
F.
G.
H.
(c) The value for the mean of the sampling distribution is: .
(d) Choose the correct distribution
A. Chi-Square Distribution
B. T-Distribution
C. Normal Distribution
Why?
A. We are provided with for the two
populations.
B. We are provided with and .
C. The size of n1 < 30 and n2 < 30
D. We are not provided with for the two
populations.
E. n1p1, n1(1-p1), n2p2, and n2(1-p2) are all greater than
5.
(e) State the decision rule:
Choose: Reject Ho and accept Ha Reject Ha and accept Ho Fail to reject Ha at = % if the p-value of the sample statistic is Choose: equal to 0.0001 less than or equal to 0.0001 greater than or equal to 0.0001 greater than or equal to 0.01 equal to 0.01 less than or equal to 0.01 .
(f) Experiment
Symbol of the sample statistic:
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
Value of the sample statistic: P-value of the sample statistic rounded to 4 decimal places:
(g) Conclusion
Choose: Fail to reject
Ha Fail to reject
Ho Reject Ho and accept
Ha Reject Ha and accept Ho
at = %
(h) Answer the question
Can the psychologist conclude that there is a significant
difference in the mean IQ score of both groups?
A. No, because the mean IQ score for female students is
significantly different than mean IQ score for male students.
B. Yes, because the mean IQ score for female students is
significantly different than mean IQ score for male students.
C. Yes, because the mean IQ score for female students is not
significantly different than mean IQ score for male students.
D. No, because the mean IQ score for female students is not
significantly different than mean IQ score for male
students.
(i) Type I Error
If a type I error were made in this test, it would mean
A. there is a significant difference in the population mean
IQ scores for female students and male students, but we incorrectly
failed to reject the null hypothesis.
B. there is no difference in the population mean IQ scores
for female students and male students, but we incorrectly rejected
the null hypothesis.
C. there is no difference in the population mean IQ scores
for female students and male students, but we incorrectly failed to
reject the null hypothesis.
D. there is a significant difference in the population mean
IQ scores for female students and male students, but we incorrectly
rejected the null hypothesis.
(j) Type II Error
If a type II error were made in this test, it would mean
A. there is no difference in the population mean IQ scores
for female students and male students, but we incorrectly rejected
the null hypothesis.
B. there is no difference in the population mean IQ scores
for female students and male students, but we incorrectly failed to
the null hypothesis.
C. there is a significant difference in the population mean
IQ scores for female students and male students, but we incorrectly
rejected the null hypothesis.
D. there is a significant difference in the population mean
IQ scores for female students and male students, but we incorrectly
failed to reject the null hypothesis.
(6 pts) A psychologist who needs two groups of students for a learning experiment decides to...
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