QUESTION 1 (15 MARKS)

a) A fast-food restaurant monitors its drive-thru service times electronically to ensure that its speed of service is meeting the company's goals. A sample of 28 drive thru times was recently taken and is shown here:

Speed of Services (in Second)

83 138 145 147

130 79 156 156

90 85 68 93

178 76 73 119

92 146 88 103

A. Construct a stem and leaf diagram of the speed of service times.

B. Identify the range of time might the restaurant say is the most frequent speed of service.

1 answer

A.
Stem and Leaf Diagram:

6 | 8 8
7 | 9
8 | 0 3 5 5 8
9 | 0 2 3 6 3
1 | 0 1 4 4 5 5 7 9 9
1 | 3
1 | 7

B. The most frequent speed of service could be in the range of 80-90 seconds, as this range has the highest number of values in the data set.