Question 4 In a clothing factory, the time taken by machines to manufacture a certain type of shirt, are assumed to be Normally distributed Not yet with a mean of 44 minutes and a standard deviation of 4 minutes. answered Marked out of a) Determine the value of t, if 10.56% of the shirts take more than t minutes to be manufactured. 4.00 b) Find the probability that a shirt picked at random, took between 42 and 51 minutes to manufacture. Flag question c) If a shirt took less than 45 minutes to be made, calculate the probability that it in fact took more than 42 minutes to make.T The owner of the factory believes that the mean time is greater than 44 minutes, due to the aging machinery. He finds that the mean manufacturing time of a random sample of 4 shirts to be 47 minutes. d) By clearly stating suitable hypotheses, test at the 5% level of significance the owner's belief Select one: O a. t = 49 0.6514 0.4847 not significant O b. t = 53 0.6514