The following are the burning times (in minutes) of chemical flares of two different formulations. The design engineers are interested in both the mean and variance of the burning times.

Type 1 Type 2 65 82 64 56 81 67 71 69 57 59 83 74 66 75 59 82 82 70 65 79

(a) Test the hypothesis that the two variances are equal. Use ???? = 0.05.

(b) Using the results of (a), test the hypothesis that the mean burning times are equal. Use ???? = 0.05. What is the P-value for this test?

(c) Discuss the role of the normality assumption in this problem. Check the assumption of normality for both types of flares.