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For each of the following examples of tests of hypotheses about \(\mu\), show the rejection and nonrejection regions on the sampling distribution of the sample mean assuming it is normal. a. A two-tailed test with \(\alpha=.01\) and \(n=100\) b. A left-tailed test with \(\alpha=.005\) and \(n=27\) c. A right-tailed test with \(\alpha=.025\) and \(n=36\)

Short Answer

Expert verified
For a two-tailed test, the rejection regions are Z \(\leq -2.576\) or Z \(\geq 2.576\), and the nonrejection region is when -2.576 \(\leq\) Z \(\leq\) 2.576. For a left-tailed test, the rejection region is when Z \(\leq -2.578\), and the nonrejection region is when Z > -2.578. For a right-tailed test, the rejection region is when Z \(\geq 1.960\), and the nonrejection region is when Z < 1.960.

Step by step solution

01

Solve test a - Two-tailed test

A two-tailed test divides the significance level across both tails of the distribution. So, for a \(\alpha = .01\), the significance level for each tail would be \(.01/2 = .005\). For \(\alpha/2 = .005\), the Z score from the Z-table is ±2.576. Hence, the rejection region is when Z \(\leq -2.576\) or Z \(\geq 2.576\), and the nonrejection region is when -2.576 \(\leq\) Z \(\leq\) 2.576.
02

Solve test b - Left-tailed test

For a left-tailed test, all the significance level rests in the left tail of the distribution. For \(\alpha = .005\), the Z score is -2.578. Therefore, the rejection region is when Z \(\leq -2.578\), and the nonrejection region is when Z > -2.578.
03

Solve test c - Right-tailed test

For a right-tailed test, the entire significance level is located in the right tail of the distribution. For \(\alpha = .025\), the Z score is 1.960. Hence, the rejection region is when Z \(\geq 1.960\), and the nonrejection region is when Z < 1.960.

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