Each week Macy's department store selects a simple random sample of 150 customers in order to learn about the amount spent per shopping trip. The historical data indicates that the population follows a normal distribution. what is the error bound value? what is the margin of error? What is the lower limit of spending?
What is the upper limit of spending?
During the most recent week of surveying; the sample mean was $82. The standard deviation historically is $20.
Use the confidence coefficient of 97.5% to help Macy's know the range of spending in a given week.