Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an X-bar chart from this data, the 3-sigma UCL would be Insert table here

A) 6.44
B) 5.87
C) 3.50
D) 2.82

Question

Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an X-bar chart from this data, the 3-sigma UCL would be Insert table here

A) 6.44 
B) 5.87 
C) 3.50 
D) 2.82

Quizplus · Accepted Answer

The formula for calculating the 3-sigma UCL for an X-bar chart is X-bar + 3*(standard deviation)/sqrt(sample size). Using the given data, we can calculate the sample mean (X-bar) to be 2.875 minutes and the sample standard deviation to be 1.051 minutes. Plugging these values into the formula yields UCL = 5.87 minutes, which is closest to choice B.

Dumplings -To-Go (DTG) Provides Take-Out Dumplings and Noodle Dishes to Customers