_ 1T.-__..-.T_._ T.___._. _ . _.___._ 1.-_T_._-J 4.A chemistry lab has an electric scale that gives a reading equal to the true weight plus a random error that is normally distributed with mean = 0 mg and standard deviation = 0.1 mg. Suppose that the results of five successive weighings of the same object are as follows (in mg): 3.162, 3.145, 3.142, 3.151, 3.152 a) Determine a 90 percent two-sided confidence interval estimate of the true weight. b) Determine a 95 percent one-sided upper confidence interval estimate of the true weight. 5. Following Question 4, for the same electric scale, which gives a reading equal to the true weight plus a random error that is normally distributed with mean = 0 mg and standard deviation = 0.1 mg. To obtain a reliable measure, we will take an average of several weighings. How many weighings should be performed so that the margin of error is within 0.02mg at the 90% confidence level? How about at 95% confidence level? Please answer both the questions or answer 5 only