Question

The values listed below windows. At Bank B, customers may enter any one of three different lines that have formed at three teler windows. Answer the following questions are waiting times (in minutes) of customers at two different banks. At Bank A, customers enter a single waiting line that feeds three teller 6.4 4.2 6.6 5.4 6.8 6.1 9.3 Bank A Bank B 8.5 5.8 click the icon to view the table of Chi-Square critical values Construct a 90% confidence interval for the population standard deviation σ at Bank A. Round to two decimal places as needed.)

And construct a 90% confidence interval for the population standard deviation at Bank B

Answer 1

s = 0.4716., n =10

chi square value for lower bound = 16.9190
chi square value for upper bound = 3.3251

(10-1) *0.4716^2/16.9190 < s^2 < (10-1) *0.4716^2/3.3251

0.12 < s^2 < 0.60

sqrt(0.12) < s < sqrt(0.60)

0.34 < sbankA < 0.77