Hi Normal Distribution: N(12, 5) = N(μ , σ ^2) μ = 10 σ = √5 Using TI or similarly an inexpensive calculator like a Casio fx-115 ES plus Using invNorm function: (a) P(X > x0) = 0.05 √5(1.645) + 12 = x0 = 15.68 give answer as directed (b) P(X < x0) = 0.98 √5(2.0537) + 12 = x0 = (c) P(X < x0) = 0.20 √5(-.8416) + 12 = x0 = (d) P(X > x0) = 0.90 √5(-1.2815) + 12 = x0 = will let You finish Up here. Wish You the Best in your Studies.