Homework Assignment #6

Statistics 220, Fall 2005

Due October 12

Show your work! Partial credit will be given on the basis of your work; writing down the answer without showing your work will get you no credit.

Non-Devore problem: Explain what is wrong with the following argument.

Suppose that X is the height of a randomly chosen person, measured in inches, and Y is the height of that same person, measured in feet. Since 12*Y = X, Var(12*Y-X) = 0. But using the rules for variance, Var(12*Y - X) = 144*Var(Y) + Var(X) > 0. What's wrong?

Problems from Devore: