1 - Menstrual cycle length. Problem 3 calculated the mean length of menstrual cycles in an SRS of 9 women. The data revealed days with standard deviation s = 2.906 days.

a - Calculate a 95% confidence interval for the mean menstrual cycle length.

b - Based on the confidence interval you just calculated, is the mean menstrual cycle length significantly different from 28.5 days at ? = 0.05 (two sided)? Is it significantly different from ? = 30 days at the same ?-level? Explain your reasoning. (Section 10.4 in your text considered the relationship between confidence intervals and significance tests. The same rules apply here.)