You have a new job as the head of an analytics group. An analyst in your group is building confidence intervals for average customers sales. You are concerned that this analyst may be making mistakes building the intervals. The analyst presents four confidence intervals, the 90%, 95%, 98% and 99%, listed below, all built off the same data. Because sample sizes are greater than 30, the analyst used the normal z-scores: 1.64, 1.96, 2.33 and 2.58, respectively. • 90% CI: ($168.80, $190.80)
• 95% CI: ($166.32 , $193.28)
• 98% CI: ($164.17, $195.43)
• 99% CI: ($162.50, $197.10)
You realize one confidence is not consistent compared to the other confidence intervals. Which confidence interval is not consistent with the other confidence intervals? Hint: Use the knowledge that all the confidence intervals are built from the same data to help you determine which confidence interval could not come from the same data as the other 3.
A. The 90% confidence interval is inconsistent with the other confidence intervals.
B. The 95% confidence interval is inconsistent with the other confidence intervals.
C. The 98% confidence interval is inconsistent with the other confidence intervals.
D. The 99% confidence interval is inconsistent with the other confidence intervals.