The Owner of Kat Motel Wants to Develop a Time

Multiple Choice

The owner of Kat Motel wants to develop a time standard for the task of cleaning a cat cage. In a preliminary study, she observed one of her workers perform this task six times, with the following results:

How many observations should be made if she wants to be 95.44 percent confident that the maximum error in the observed time is 2 seconds? Assume that the standard deviation of the task time is 6 seconds.

A) 5
B) 6
C) 30
D) 36
E) 49