How many tissues should a package of tissues contain? Researchers determined that 68 tissues is the avg. number of tissues used during a cold. Suppose a random sample of 100 tissues users yielded the following data o the number of tissues used during a cold:

x-bar = 63, s = 17

Suppose the alternative we wanted to test was Ha: µ < 68. State the correct rejection region for α = .05.

**Solution: **The alternative hypothesis tells us that we have a left-tailed test. For a 0.05 significance level, we have that the critical value is -1.96. The critical region is then

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In our example, the z-statistics is computed as

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That means that we reject the null hypothesis and accept the alternative.

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