Assume that s1 2

= s2 2

= s2. Calculate the pooled estimator LO5 of s2 for each of the following cases:

a. s1 2

= 180, s2 2

= 200, n1 = n2 = 25

b. s1 2

= 25, s2 2

= 40, n1 = 10, n2 = 20

c. s1 2

= .25, s2 2

= .32, n1 = 8, n2 = 12

d. s1 2

= 2300, s2 2

= 2000, n1 = 15, n2 = 18

e. Note that the pooled estimate is a weighted average of the sample variances. To which of the variances does the pooled estimate fall nearer in each of cases a–d?