In: Statistics and Probability
The values listed below are waiting times (in minutes) of customers at two different banks. At Bank A, customers enter a single waiting line that feeds three teller windows. At Bank B, customers may enter any one of three different lines that have formed at three teller windows. Answer the following questions.
Bank A |
6.5 |
6.6 |
6.7 |
6.8 |
7.1 |
7.2 |
7.5 |
7.9 |
7.9 |
7.9 |
|
---|---|---|---|---|---|---|---|---|---|---|---|
Bank B |
4.2 |
5.4 |
5.8 |
6.2 |
6.8 |
7.7 |
7.7 |
8.5 |
9.3 |
10.00 |
a) Using Chi-Square critical values construct a 90% confidence interval for the population standard deviation σ at Bank A.
b) Construct a 99% confidence interval for the population standard deviation σ at Bank A.
c) Construct a 99% confidence interval for the population standard deviation σ at Bank B.
Interpret the results found in the previous parts. Do the confidence intervals suggest a difference in the variation among waiting times? Does the single-line system or the multiple-line system seem to be a better arrangement?
A.
The variation appears to be significantly lower with a single line system. The single-line system appears to be better.
B.
The variation appears to be significantly lower with a single line system. The multiple-line system appears to be better.
C.
The variation appears to be significantly lower with a multiple-line system. The single-line system appears to be better.
D.
The variation appears to be significantly lower with a multiple-line system. The multiple-line system appears to be better.