BA 275 Quantitative Business Methods

BA 275Quantitative Business Methods Agenda • Quiz #7 • Analyzing Survey Data • Hypothesis Testing for Proportion(s) • Chi-square Test of Independence • Contingency Tables

Final Examination • Tuesday, 3/20/2007 from 4:00 – 5:50 p.m. • Room: GLFN Auditorium • Check the seating chart when you arrive. You must sit in the assigned seat to receive your own exam booklet. • Topics: Comprehensive • Regression analysis accounts for 50%. • Need a calculator that works and a good night sleep. • The normal, t and c2 tables (Tables A, D, and F) will be provided. • A 4” x 6” index card is allowed. • Additional office hours during the finals week • Monday, 3/19/2007, 1:00 – 3:00 p.m. • Tuesday, 3/20/2007, 9:00 – 11:00 a.m. • Tuesday, 3/20/2007, 1:00 – 3:30 p.m.

Analyzing Categorical Data • Do you own an iPod? ___Yes ___No • Do you own a XBoX? ___Yes ___No • Which of the following 4 soft drinks gives you the highest satisfaction? • Type A ___ • Type B ___ • Type C ___ • Type D ___ • Your gender: ____Male ____ Female • Your nationality: _____

Central Limit Theorem • In the case of sample mean • In the case of sample proportion

Example 1 • Three politicians are attempting to win the Democratic nomination for senator. • The result of a survey of 1000 Democrats is summarized below. • Do we have enough evidence to indicate that Candidate A will receive more than 50% of the vote? Assume a = 5%. (use the rejection region and the p-value approaches.) • Estimate with 95% confidence the true proportion?

Example 2 • In recent years over 70% of first-year college students responding to a national survey have identified “being well-off financially” as an important personal goal. A state university finds that 153 of a random sample of 200 of its first-year students say that this goal is important. • Do we have evidence to support that more than 70% of first-year students would identify being well-off as an important personal goal? (use the rejection region and the p-value approaches.) Assume a = 5%.

Example 3 • A financial analyst wanted to determine the mean annual return on mutual funds. In a random sample of 15 returns she found a sample mean of 12.9% with a (sample) standard deviation 3%. • Is there evidence to claim that the mean annual return on mutual funds is greater than 12%? Assume a = 5%.

Two-Sample Inference on p1 – p2 Population #1 Population #2 Sample #1 Sample #2

Example 4 • Five months ago, a poll showed that 579 out of 908 voters in a sample supported the WaterFront project. This month, 360 out of 812 voters in a sample support the project. • Is the project losing support? Assume a = 5%.

Contingency Table

Answer Key to Examples 1 – 3 • Example 1. See Example 3 in the 3-7-07 slides (p.19) • Example 2. See Example 4 in the 3-7-07 slides (p.20) • Example 3. See Example 5 in the 3-7-07 slides (p.20)

Answer Key to Example 4p1: % of support 5 months ago and p2: % of support nowH0: p1 = p2 vs. Ha: p1 > p2 • Textbook Approach (using the pooled estimate): Reject H0 if z > 1.645 • In-Class Approach: Reject H0 if z > 1.645

BA 275 Quantitative Business Methods