Body mass index is calculated by dividing a person's weight by the square of his or her height; it is a measure of the extent to which an individual is overweight. For the population of middle-aged men who later develop diabetes mellitus, the distribution of baseline body mass indices is approximately normal with an unknown mean μ and a standard deviation σ. A sample of 58 men selected from this group has mean x-bar = 25.0 kg/m2 and standard deviation s = 2.7 kg/m2.
a. Construct a 95% confidence interval for tech population mean μ.
b. At the 0.05 level of significance, test whether the mean baseline body mass index for the population of middle aged men who develop diabetes is equal to 24.0 kg/m2, the mean for the population of men who do not. What is the p-value of the test?
c. What do you conclude?
d. Based on the 95% confidence interval, would you have expected to reject or to not reject the null hypothesis? Why?