How many observations should be made if the analyst wants to be 99.74 percent confident that the maximum error in the observed time is two seconds? Assume that the standard deviation of each task time is 4 seconds.
A)5
B)6
C)25
D)36
E)49

Question

Quizplus · Accepted Answer

The correct answer is D.The sample size required to achieve a 99.74% confidence level with a maximum error of 2 seconds and a standard deviation of 4 seconds is 36. This can be calculated using the formula: n = (Z^2 * s^2) / e^2, where Z is the z-score corresponding to the desired confidence level, s is the standard deviation, and e is the maximum error.

How Many Observations Should Be Made If the Analyst Wants