The recommended daily dietary allowance for zinc among males older than age 50 years is 15 mg/day. The article "Nutrient Intakes and Dietary Patterns of Older Americans: A National Study" (J. of Gerontology, 1992: M145–150) reports the following summary data on intake for a sample of males age 65–74 years: n=115, barx =11.3, and s=6.43. Does this data indicate that average daily zinc intake in the population of all males ageing 65–74 falls below the recommended allowance?
A. State the null and alternative hypotheses.
B. Calculate the test statistic
C. Define the rejection region at ?=0.05.
D. Make a decision about the test and interpret.
E. Find the p-value corresponding to the test and based on which make a decision about the test. (The decision should be the same with D.)