A population has a mean of 300 and a standard deviation of 50 . Suppose a simple random sample of size 125 is selected and x is used to estimate . Use z-table. a. What is the probability that the sample mean will be within \pm 4 of the population mean (to 4 decimals)? b. What is the probability that the sample mean will be within \pm 10 of the population mean (to 4 decimals)?.