Data set 16 in Appendix B lists the sugar content (grams of sugar per gram of cereal) for a sample of different cereals. Those amounts are summarized with these statistics: n= 16, xbar= 0.295, s= 0.168g. Use a 0.05 significance level to test the claim of a cereal lobbyist that the mean for all cereals is less than 0.3g.

**Solution: **We need to test the following hypotheses:

_{}

We use a t-test (the sample size is not big enough to use normal approximation), and we compute the t-statistics as:

_{}

The critical value for this left-tailed test is -1.753, which means that we cannot reject the null hypothesis. That implies that *we don’t have enough evidence to support the claim that the mean for all cereals is less than 0.3g*.

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