(a) A sample of 200 women from the labour force found an average wage of £6000 p.a. with standard deviation £2500. A sample of 100 men found an average wage of £8000 with standard deviation £1500. Estimate the true difference in wages between men and women.

(b) A different survey, of men and women doing similar jobs, obtained the following results:

x̅_W = £7200  x̅_M = £7600

s_W = £1225  s _M = £750

n_W = 75  n _M = 50

Estimate the difference between male and female wages using these new data. What can be concluded from the results of the two surveys?