Compute the pooled estimate of ???? = ???????? = ???????? used in the large sample ????-test of the difference of two proportions when

(a) ˆ???????? = 0.42, ˆ???????? = 0.51, ???????? = 85, and ???????? = 110.

(b) ˆ???????? = 0.54, ˆ???????? = 0.49, ???????? = 210, and ???????? = 190.

(c) ˆ???????? = 0.76, ˆ???????? = 0.62, ???????? = 125, and ???????? = 145.

(d) ˆ???????? = 0.08, ˆ???????? = 0.15, ???????? = 250, and ???????? = 300.