Microwave Popcorn. Two brands of microwave popcorn, which we will call Brand A and Brand B, were compared for consistency in popping time. The popping times, in seconds, for 30 bags of each brand are provided on the WeissStats site. Use the technology of your choice to do the following.

a. Obtain normal probability plots and boxplots, and histograms for the two data sets.

b. Based on your graphs from part (a), do you think it reasonable to perform a two-standard-deviations F-test on the data? Explain your answer.

c. At the 5% significance level, do the data provide sufficient evidence to conclude that Brand B has a more consistent popping time than Brand A?

d. Find a 90% confidence interval for the ratio of the standard deviations of popping times for Brand A and Brand B.