b) Simple random samples of participants were taken and the LDL cholesterol levels are assumed to be normally distributed. Check that the assumption of equal variances has also been satisfied. c) Conduct a hypothesis test at =0.05 to determine if the mean LDL cholesterol levels differ. (Note: You do not need to include the ANOVA table in the body of the test.) .. . 8. Engineers must consider the breadths of male heads when designing motorcycle helmets. Men have breadths that are normally distributed u = 6.0 inches and o = 1.4 inches. [6] a) If 80 males are randomly selected, find the probability that the mean head breadth is less than 6.1 inches. b) A production manager views the results from b) and suggests that they manufacturer