pcterry New Recruit 47 Posts user info edit post |
This data set Credit Card Charges contains last month's credit card purchases of 500 customers randomly selected from all customers of URBroke, a major credit card company. The marketing department of URBroke is considering a special offer for URBroke credit card holders who spent $1000 or more last month on their card. Question 1. From these data construct a 95% confidence interval for the proportion of all URBroke credit card holders who will qualify for the promotion. NOTE: calculate the standard error of to 3 decimal places. HINT - either of the following will help: in cell B3 type =IF(A3>=1000,1,0), then press Enter; click on cell B3, then double-click on the small dark square in the lower right corner of B3; then sum B3:B502. order cells A3:A502 from largest to smallest by clicking the "Sort and Filter" icon at the right end of the Home tab menu ribbon. lower bound upper bound.
Historically, the percentage of URBroke customers who spent $1000 or more in any given month on their credit card has been 11%, and the marketing department wonders if the percentage has increased because of economic conditions. So the marketing department performs the hypothesis test H0: p = 0.11 HA p > 0.11, where p is the proportion of URBroke customers who spend more than $1,000 on their credit card in a month. Question 2. What is the value of the test statistic for this hypothesis test? NOTE: calculate the standard error of to 3 decimal places. Question 3. What is the P-value for this hypothesis test? Question 4. What is the correct conclusion for this hypothesis test? Do not reject the null hypothesis and conclude that the proportion of URBroke customers who spend more than $1,000 per month on their credit card is not significantly different from the historical value of 0.11. Do not reject the null hypothesis and conclude that the proportion of URBroke customers who spend more than $1,000 per month on their credit card has decreased from the historical value of 0.11. Reject the null hypothesis and conclude that the proportion of URBroke customers who spend more than $1,000 per month on their credit card has decreased from the historical value of 0.11. Accept the null hypothesis that the proportion of URBroke customers who spend more than $1,000 per month on their credit card is 0.11 since the P-value is less than 0.05. Reject the null hypothesis and conclude that the proportion of URBroke customers who spend more than $1,000 per month on their credit card has increased from the historical value of 0.11. 7/8/2011 10:24:10 PM |