Exam1_practice_solutions

Exam1_practice_solutions - 5E practice problems for exam 1...

Info iconThis preview shows page 1. Sign up to view the full content.

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

Unformatted text preview: 5E practice problems for exam 1 1. (a) 212 + 36 = 248 out of the 500 husbands earn less than $75 , 000. So 248 500 = . 496. (b) Out of the 252 couples that have husbands with income over $75 , 000, 54 of the wives also earned more than that amount. So the probability is 54 252 = . 214. We could also think of this as P ( W | H ) = P ( H & W ) P ( H ) = 54 / 500 248 / 500 = . 214, where H is the event that the husband earns over 75, and W is the event that the wife does. 2. If A is the event that Bill will drive the Honda, and B is is the event that he does not have car problems, we are given P ( A ) = 1- . 8 = . 2, and P ( B | A ) = . 60. So P ( A & B c ) = P ( A ) P ( B c | A ) = (1- . 6) . 2 = . 08. 3. (a) First question: Using the binomial distribution, we want the probability of 2 successes with n = 5 and p = . 3. This is C (5 , 2) ( . 3) 2 ( . 7) 3 = . 3087. Second question: The probability of no more than 1 is f (0)+ f (1) = C (5 , 0) ( . 3) ( . 7) 5 + C (5 , 1)...
View Full Document

Ask a homework question - tutors are online