Exercise1: Find 90% Confidence Interval for the population Mean in the following case (consider the population is normally distributed) 1. Sample standard deviation =5, sample size =10, Sample mean =15 2. Population standard deviation is 7, sample size is 20 , Sample mean is 77 Exercise2: The following data represent a sample of the monthly salary of 8 instructors in a privet school in Oman. Find the 90% confidence interval of the population mean. 700600650400540430340 Exercise3: A random sample of 200 persons from Jordan has a mean age of 32 and sample standard deviation =9, Find the 95% confidence interval of the population mean. Consider Level of significance =0.05