Question: Suppose that household incomes (annually) in an area are normally distributed with a mean of £27,000 and an s.d. of £5,200.

a) Find what proportions of these households have incomes:

I. greater than £30,000 (1 marks)

II. less than £21,000 (1 marks)

III. between £25,500 and £31,500 (1 marks)

b) Find the upper quartile income (i.e. the income boundary of the top 25%) (1 marks)