a) Pr(171 < X < 182) = Pr(X < 182) - Pr(X < 171). Convert into X = 182 and X = 171 into z-values and use your tables: .

b) ~ Normal . Calculate .

c) Go to your formula for the confidence interval of a mean, substitute the appropriate data and solve for n.

d) Find the value of x* such that . Then calculate Pr(Y < x*) and multiply the answer by 100 to convert into a %.

Note: .