Question

BearCo produces alutin (and alloy of aluminium and tin) bearings for truck engines. Prior to shaping, ingots

Answer 1

Let x be a random variable representing the mean thickness of alutin.

a.) P(2.97 < x < 3.08) = P((2.97 - 3.05)/0.025 < z < (3.08 - 3.05)/0.025) = P(-3.2 < z < 1.2) = P(z < 1.2) - P(z < -3.2) = P(z < 1.2) - [1 - P(z < 3.2)] = P(z < 1.2) + P(z < 3.2) - 1 = 0.88493 + 0.99931 - 1 = 0.88424