# 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**:

- Problem 5.46
- Problem 5.48
- Problem 5.49
- Problem 5.50
- Problem 5.60
- Problem 5.62
- Problem 5.66, parts (a), (b), (c), and (d).