Question

During the course of her study, a researcher couldn’t help but wonder if adult males in the United
States had significantly higher blood sugar levels than adult females. To address this question, the researcher
randomly measured fasting blood sugar levels of 20 adult males and 22 adult females. The mean blood sugar
level for the 20 males was 118 mg/dL with a standard deviation of 24 mg/dL. The mean blood sugar level for the
22 females was 100 mg/dL with a standard deviation of 26 mg/dL.
(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