Determine the sample size n needed to construct a 90% confidence interval to estimate the population mean for the following margins of error when a= 69. a) 10 b) 15 c) 20 Click the icon to view a table of standard normal cumulative probabilities. a) n- (Round up to the nearest integer.) Enter your answer in the answer box and then click Check Answer. parts remaining Clear All MacBook Air esc 838 F4 $ & 1 2 3 4 6 8 Q W R Y tab