Question

North Carolina has developed a large hog industry, in part to replace the declining tobacco
industry in that state. Someone in the hog industry wants to know if North Carolina pigs weigh significantly more
than U.S. pigs in general. A sample of 18 North Carolina pigs shows a mean weight of 66.5 kg with a standard
deviation of 4.5 kg. From the U.S. Department of Agriculture, we learn that the entire U.S. population of
American pigs has a mean pig weight of 65 kg.
(a) What is the null hypothesis for this problem? What is the alternative hypothesis?
(b) For this problem, would you perform a one- or two-tailed test? Explain how you reached that decision.
(c) Determine which procedure (you have learned five situations) is the appropriate statistical test to use, with
a clear explanation for your choice.
(d) Using your calculator, test the null hypothesis, present your results. Show all your work.
(e) Using statistical language (“statistic-ese”), state your conclusion and your reasoning for reaching this
conclusion. Then restate your conclusion, this time in English instead of “statistic-ese,” without including
statistical symbols or the term hypothesis. (What is the answer to the researcher’s question?)
(f) State, based on your conclusion, whether you may have committed a Type I error or a Type II error, and
what that means.

Answer 1