# 9051 then pm w 0 pz 0 539051 pz 128

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

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

Unformatted text preview: a randomly selected married man and let W be the height of a randomly selected married woman. Then M - W has a distribution that is approximately normal with µ M −W = 70 − 65 = 5 2 2 σ M −W = σ M + σ W = 3 2 + 2.5 2 = 15.25 = 3.9051 Then P(M - W &lt; 0) = P(Z &lt; (0-5)/3.9051) = P(Z &lt; -1.28) = .100 Part (b) is Essentially correct if calculates the mean and standard deviation of M-W (or W-M) correctly, and then correctly calculates the appropriate probability. Partially correct if calculates the mean and/or standard deviation incorrectly, but then uses these values and a correct process to compute an appropriate probability OR computes the mean and standard deviation correctly but is unable to compute the appropriate probability. Copyright © 2000 College Entrance Examination Board and Educational Testing Service. All rights reserved. AP is a registered trademark of the College Entrance Examination Board. AP® Statistics 2000 ─ Scoring Guidelines c. Based on the answer to part (b), if heights of husbands and heights of wives were independent, would expect approximately 10% of married couples to have the wife taller than the husband. Based on the interval in part (a), the estimate of the percent of married couples with the wife taller than the husband was between 3% and 7%. This is smaller than what we would have expected to see if the heights of husbands and wives were independent. So, the data suggests that heights of husbands and wives are not independent. Part (c) is Essentially correct if correctly judges independence (dependence) based on responses in parts (a) and (b) and gives a good explanation relating the probability in part (b) with the interval in part (a). Partially correct if judgment of independence is consistent with the responses in parts (a) and (b), but explanation is weak or poorly linked to parts (a) and (b). Notes: 1. If the explanation compares the point estimate in (a) with the probability in (b), this is considered a weak argument. 2. If explana...
View Full Document

## This note was uploaded on 09/06/2013 for the course MATH AP Statist taught by Professor Mosby during the Spring '13 term at Silverton High School, Silverton.

Ask a homework question - tutors are online