Solutions HWA3

11.4: Pr(K < 120) = (CC) Pr(K < 119.5) =(NA) Pr(Z < (119.5 – 150)/sqrt[(1000)(.15)(.85)]) = .0035

11.8: First convert question about sample p to one about sample K.

Pr( .42 <= p <= .50) = Pr (21 <= K <= 25) =(CC) Pr(20.5 < K < 25.5) =NA Pr(-.71 < Z < .71) = .5219

This problem could have also been done without CC and NA.

11.12: Here mu_{SUM} = (n)(mu) = (80)(150) = 12000, sigma_{SUM} = sqrt[n](sigma) = sqrt[80](32) = 286.2167

Pr(SUM > 13600) = Pr( Z > 5.59) = (off the chart) 0