+ QB ADV Activity 11 1. Bank of New York would like to test the hypothesis that the average checking account balance for younger customers (under 40 years old) is different from the average checking account balance for older customers (40 or more years old). The following data summarizes the sample statistics of the checking account balances for customers in each age group. Assume that normality is satisfied and the population variances are unequal Younger| Older Sample mean $1150 $1230 Sample size 16 14 Sample standard deviation $100 $70 Define Population 1 as younger customers and Population 2 as older customers and use the p-value approach to test this hypothesis with a = 0.05. Ho : HA : P-value: Conclusion: 2. Suppose Holiday Inn has developed a new training program for hotel staff in an effort to increase customer satisfaction. The employees at the Newark location completed the training while the employees at the Concord location did not. Holiday Inn would like to test the hypothesis that the average customer satisfaction score at the Newark location is higher than the average satisfaction score at the Concord location. The following data summarizes the sample statistics for customer satisfaction, on a scale of I to 100. for each location. Assume that normality is satisfied and the population variances are unequal. Newark | Concord Sample mean 82.6 Sample size 25 20 Sample standard deviation 5.0 6.0 Define Population 1 as the Newark location and Population 2 as Concord location and use the p-value approach to test this hypothesis with a = 0.01. Ho : HA : P-value:' Conclusion: 994 OLOZ P hp+ 3. An SAT prep course claims to increase students scores by more than 60 points. A group of 9 students who have previously taken the SAT are chosen to take the prep course. Their SAT scores before and after completing the prep course are listed below. Assuming normality is satisfied, test the claim using significance level a = 0.01. Participant 2 3 4 5 6 8 9 Pre-course score 1010 980 1170 1200 1040 1280 1450 1470 1500 Post-course score 1100 1260 1190 1280 1170 1370 1440 1500 1520 Ho : HA P-value: Conclusion: 4. Trace metals in drinking water affect the flavor and an unusually high concentration can pose a health hazard. Ten pairs of data were taken measuring zine concentration in bottom water and surface water. Does the data suggest that the true average concentration in the bottom water exceeds that of surface water? Assuming normality is satisfied, use a = .05 to perform appropriate hypothesis testing. Location 4 6 9 10 Zine concentration .430 266 1567 :531 707 651 .589 .469 1.123 in bottom water Zinc concentration .415 390 .410 LOUS 523 .612 in top water Ho : HA : P-value:' Conclusion: OLDE X hp