A marketing executive wants to understand the differences in customer satisfaction scores between two companies offering the same service. The executive collects the following data for customer satisfaction. Assume the two populations have the same variance. What is the lower bound of the 99% confidence interval for the mean difference (Company 1 minus Company 2) in customer satisfaction scores? Round your answer to two decimal places. Answer = Assume that higher numerical values correspond to increased customer satisfaction. Choose all the appropriate conclusions from your analysis. - Because the confidence interval for company 1 minus company 2 satisfaction levels spans zero, we cannot reject the null hypothesis of equal means in favor of the the alternative hypothesis of unequal means at the 1% significance level and thus conclude that the companies have about equal mean customer satisfaction levels. - We cannot draw any conclusions because we did not find the upper limit of the confidence interval. - Because the 99% confidence interval for company 1 minus company 2 satisfaction levels only contains negative values, we reject the null hypothesis of equal means in favor of the the alternative hypothesis of unequal means at the 1% significance level. Thus it appears that company 1 has higher satisfaction than company 2. - Because the 99% confidence interval for company 1 minus company 2 satisfaction levels only contains positive values, we reject the null hypothesis of equal means in favor of the the alternative hypothesis of unequal means at the 1% significance level. Thus it appears that the two companies have unequal mean customer satisfaction levels. Company 1 Company 2 1 4 7 1 10 0 3 2 7 0 8 2 3 2 6 3 7 2 1 2 7 4 9 6 9 3 4 0 10 2 8 1 9 10 8 7 5 0 10 1 2 4 3 7 2 0 9 10 8 1 3 3 5 2 8 2 9 10 7 6 4 8 4 3 1 5 0 4 5 2
A marketing executive wants to understand the differences in customer satisfaction scores between two companies offering the same service. The executive collects the following data for customer satisfaction. Assume the two populations have the same variance.
What is the lower bound of the 99% confidence interval for the mean difference (Company 1 minus Company 2) in customer satisfaction scores? Round your answer to two decimal places.
Answer =
Assume that higher numerical values correspond to increased customer satisfaction. Choose all the appropriate conclusions from your analysis.
- Because the confidence interval for company 1 minus company 2 satisfaction levels spans zero, we cannot reject the null hypothesis of equal means in favor of the the alternative hypothesis of unequal means at the 1% significance level and thus conclude that the companies have about equal mean customer satisfaction levels.
- We cannot draw any conclusions because we did not find the upper limit of the confidence interval.
- Because the 99% confidence interval for company 1 minus company 2 satisfaction levels only contains negative values, we reject the null hypothesis of equal means in favor of the the alternative hypothesis of unequal means at the 1% significance level. Thus it appears that company 1 has higher satisfaction than company 2.
- Because the 99% confidence interval for company 1 minus company 2 satisfaction levels only contains positive values, we reject the null hypothesis of equal means in favor of the the alternative hypothesis of unequal means at the 1% significance level. Thus it appears that the two companies have unequal mean customer satisfaction levels.
Company 1 | Company 2 |
1 | 4 |
7 | 1 |
10 | 0 |
3 | 2 |
7 | 0 |
8 | 2 |
3 | 2 |
6 | 3 |
7 | 2 |
1 | 2 |
7 | 4 |
9 | 6 |
9 | 3 |
4 | 0 |
10 | 2 |
8 | 1 |
9 | 10 |
8 | 7 |
5 | 0 |
10 | 1 |
2 | 4 |
3 | 7 |
2 | 0 |
9 | 10 |
8 | 1 |
3 | 3 |
5 | 2 |
8 | 2 |
9 | 10 |
7 | 6 |
4 | 8 |
4 | 3 |
1 | 5 |
0 | 4 |
5 | 2 |
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