The mean IQ score of humans is 100 Suppose the
The mean IQ score of humans is 100. Suppose the director of Institutional Research at Joliet Junior College (JJC) obtains a simple random sample of 40 JJC students and ﬁnds the mean IQ is 103.4 with a standard deviation of 13.2.
(a) Consider the hypotheses H0: µ = 100 versus H1: µ > 100. Explain what the director of Institutional Research is testing. Perform the test at the α = 0.05 level of signiﬁcance. Write a conclusion for the test.
(b) Consider the hypotheses H0: µ = 101 versus H1: µ > 101. Explain what the director of Institutional Research is testing. Perform the test at the α = 0.05 level of signiﬁcance. Write a conclusion for the test.
(c) Consider the hypotheses H0: µ = 102 versus H1: µ > 102. Explain what the director of Institutional Research is testing. Perform the test at the α = 0.05 level of signiﬁcance. Write a conclusion for the test.
(d) Based on the results of parts (a)–(c), write a few sentences that explain the difference between “accepting” the statement in the null hypothesis versus “not rejecting” the statement in the null hypothesis.
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