The owners of a small mail order business want to estimate their average annual sales. They randomly select 100 sales from their first quarter to analyze. For the samples, the average amount spent was $235.12 with a standard error of $12.41.

Use what you have learned about sampling distributions to answer the following questions:

What conditions, or assumptions, should be verified before using the sample values to estimate the population mean?

If these conditions are satisfied, what is the probability that you would get a sample with a sample mean of $230.00 or less?

If they expect to have 50,000 sales this year, what is their expected value of the total sales for the year?

What do the following two values represent, in terms of the sampling distribution

X+Z0.05

n

=214.77

X+Z0.95

n

=255.47