In: Statistics and Probability
A population has a mean of 400 and a standard deviation of 90. Suppose a sample of size 125 is selected and x bar is used to estimate mu.
a. What is the probability that the sample mean will be within +/- 5 of the population mean (to 4 decimals)? (Round z value in intermediate calculations to 2 decimal places.)
b.What is the probability that the sample mean will be within +/- 10 of the population mean (to 4 decimals)? (Round z value in intermediate calculations to 2 decimal places.)