For each of the following situations, find the critical value(s) for z or t.

a. H ₀ : p = 0.6 vs H _A : p ≠ 0.6 at α = 0.01

b. H ₀ : p = 0.7 vs H _A : p > 0.7 at α = 0.01

c. H ₀ : μ = 20 vs H _A : μ ≠ 20 at α = 0.01; n = 38

d. H ₀ : p = 0.6 vs H _A : p > 0.6 at α = 0.10; n = 335

e. H ₀ : μ = 30 vs H _A : μ < 30 at α = 0.01; n = 1000