Asimple random sample of 90 is drawn from a normally distributed population, and the mean is found to be 138, with a standard deviation of 34. what is the 90% confidence interval for the population mean? use the table below to you answer the question. confidence level 90% 95% 99% z*-score 1.645 1.96 2.58 remember, the margin of error, me, can be determined using the formula mc021-1.jpg. 128.75 to 147.25 130.98 to 145.02 132.10 to 143.90 137.38 to 138.62