A Methods and Measurement Analyst Wants to Develop a Time

Multiple Choice

A methods and measurement analyst wants to develop a time standard for a certain task. In a preliminary study, he observed one worker perform the task six times with an average observed time of 20 seconds and a standard deviation of two seconds.
How many observations should be made if he wants to be 95.44 percent confident that the maximum error in the observed time is one second?

A)  3
B)  4
C)  13.3
D)  16
E)  25