An SRS of size 120 taken from a population having proportion of
successes p1 = 0.40 yields 42 successes. An independent SRS of size
100 taken from a population having proportion of successes p2 =
0.30 yields 22 successes. Reference: Ref 8-8 The sampling
distribution for the difference in the sample proportions, – , has
mean: 0.29. 0.13. 0.35. 0.10.