Answer to Question #246775 in Management for ken

Question

For Sunny Dale Bank the time required to serve customer at the drive by window is an important quality factor in competing with other banks in the city. (Show your computation)

a) Mean time to process a customer at the peak demand period is 5 minutes
b) Standard deviation of 1.5 minutes
c) Sample size of six customers
d) Design an X bar Chart that has type I error of 5% (z= 1.96)
e) After several weeks of sampling, two successive samples came in at 3.70 and 3.68 minutes respectively
f) Is the customer service process in statistical control?

Answer 1

The Sunny Dale Bank monitors the time required to serve customers at the drive-through window because it is an important quality factor in competing with other banks in the city. After analyzing the data gathered in an extensive study of the window operation, bank management determined that the mean time to process a customer at the peak demand period is 5 minutes, with a standard deviation of 1.5 minutes. Management wants to monitor the mean time to process a customer by periodically using a sample size of six customers. Assume that the process variability is in statistical control. Design an x-chart that has a type I error of 5 percent. That is, set the control limits so that there is a 2.5 percent chance a sample result will fall below the LCL and a 2.5 percent chance that a sample result will fall above the UCL.