CS 237, Fall 2007

Assignment #7

Date Due: Tuesday, December 11

Reading: Chapter 6, pages 126-133 .

Problems:

1. Page 119, problem 5.5

2. Page 120, problem 5.6

3. Page 123, problem 5.21 (a) and (b).

4. Assume that the lifetime X of an XBOX (in weeks) is exponential with parameter 120. (See page 196 of the text for details of exponential distributions. )

(a) What is the probability that the XBOX will last more than 240 weeks?

(b) If the XBOX is still working after 100 weeks, find the probability that it will last more than 340 weeks.

5. page 219, #8.3