Mean amount bought by a typical customer at Churchill's Grocery Store is $23.50 with standard deviation of $5.00. Suppose the distribution of amounts purchased follows normal distribution. For sample of 50 customers, reply the following questions.
a. Determine the probability the sample mean is at least $25.00?
b. Determine the probability the sample mean is greater than $22.50 but less than $25.00?
c. Within what limits will 90 percent of the sample means occur?