3. The following earnings data represent random samples drawn from male and female company executives in the United Kingdom.

Male and Female Executive Earnings

Male Earnings -	Female Earnings -
50100	41200
47800	36600
45000	44500
51500	47800
55000	42500
53850	47500
51500	40500
63900	28900
57800	48000
61100	42300
51000	40000
	31400

(a) Use a significance level of 0.05 to ascertain if earnings variability is different across gender.

(b) Use a t-test and a significance level of 0.05 to establish whether, on average, a male chief executive earns significantly more than a female chief executive.