hw3ma540

# hw3ma540 - Homework 3 1 Problem 8 Page 228 Suppose that 10...

This preview shows pages 1–2. Sign up to view the full content.

MA540 Page | 1 Homework 3 1) Problem 8 Page 228 Suppose that 10 trains arrive independently at a station every day, each at random time between 10:00am and 11:00am. What is the expected number and the variance of those that arrive between 10:15am and 10:28am? Solution: Call a train that arrives between 10:15am and 10:28am a success. Then p , the probability of success is Therefore, the expected value and the variance of the number of trains that arrive in the given period are 2) Problem 9 Page 228 Suppose that a certain bank returns bad checks at a Poisson rate of three per day. What is the probability that this bank returns at most four bad checks during the next two days? Solution: The number of checks returned during next two days is Poisson with . The desired probability is 3) Problem 14 Page 229 Past experience shows that 30% of the customers entering Harry’s Clothing Store will make a purchase. Of the customers who make a purchase, 85% use credit cards. Let X be the number of the next six customers who enter the store, make a purchase, and use a credit card. Find the probability mass function, the expected value, and the variance of X

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 6

hw3ma540 - Homework 3 1 Problem 8 Page 228 Suppose that 10...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online