Homework help

Determine the minimum sample size required when you want to be 90% condent that the sample mean is within one unit of the population mean and a = 12.5. Assume the population is normally distributed. A 90% condence level requires a sample size of D. (Round up to the nearest whole number as needed.) Enter your answer in the answer box and then click Check Answer. You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. From a random sample of 80 dates, the mean record high daily temperature in a certain city has a mean of 83.43 F. Assume the population standard deviation is 15.22 F. The 90% confidence interval is ( (Round to two decimal places as needed.)