Question: The British Institute of Management (BIM) wishes to have information on the mean income of middle managers in the retail industry. A random sample of 256 managers reveals a sample mean of £45,420. The standard deviation of this sample is £2,050. The association would like answers to the following questions:

(a) What is the best estimate you can give of the population mean?

(b) Give a 5% (+ / -) range of values for the population mean?

(c) What do the numbers given for b) actually mean?