Consider a sample of 30 WMU engineering alumni. The population average salary is $55,000 and amongst the 30 alumni the sample standard deviation is $12,000. Assuming the population is normally distributed answer the following:
A. What is the probability that the average salary of the sample is greater than $60,000?
B. What is the probability that the average salary of the sample is between $50,000 and $54,000?
C. What is the probability that the average salary of the sample is less than $48,000?