Q.4 The Bureau of Labor Statistics provides compensation information on and services for various positions. As of May 2008, the national average salary for an RN (registered nurse) was $65,130. Suppose the standard deviation is $9385. For a random sample of 100 such nurses find the following:
(a) The probability that the mean of the sample is less than $62,500.
(b) The probability that the sample mean is between $64,000 and $67,500
(c) The probability that the sample mean is greater than $66,000
(d) Explain why the assumption of normality about the distribution of wages was not involved in the solutions parts to a, b, and c.