Hello, please let me know step by step how is 208.987 the correct answer.

Question 4 0/1 pts The management of the Diners Delight restaurant chain is in the process of establishing quality control charts for the time that its service people give to each customer. Management thinks the length of time that each customer is given should remain within certain limits to enhance service quality. For simplicity, the data from three samples are displayed below. In each sample, five service people were randomly selected, and the customer service they provided was observed. The time (in seconds) to service each customer was recorded as below. Service Sample 1 Sample 2 Sample 3 person (morning) (afternoon) (evening) #1 196 196 201 205 #3 201 208 211 #4 195 202 206 200 202 What is the upper controllimit of the X-bar chart for a 99.73% (3-sigma) quality limit? #2 206 210 #5 203 Numbers only, keep 3-decimal if not exact, either round up or down is ok. You Answered 208.955 Correct Answer 208.987 margin of error +/- 0.001