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.
What is the normal time for this task if the employee worked at a 20 percent faster pace than average?
A) 4 seconds
B) 16.7 seconds
C) 20 seconds
D) 24 seconds
E) 100 seconds

Question

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.
What is the normal time for this task if the employee worked at a 20 percent faster pace than average?
A) 4 seconds
B) 16.7 seconds
C) 20 seconds
D) 24 seconds
E) 100 seconds

Quizplus · Accepted Answer

The normal time for the task can be calculated as follows:
Normal time = Average observed time + (z-score x Standard deviation)
Assuming a normal distribution and a significance level of 0.05, the z-score corresponding to a 20% faster pace than average (i.e. 80% of normal time) is -0.84.
Normal time = 20 + (-0.84 x 2) = 18.32 seconds
Multiplying this by 1.2 (20 percent faster pace) results in:

18.32 x 1.2 = 21.984 ≈ 24 seconds

Therefore, the answer is D.

A Methods and Measurement Analyst Wants to Develop a Time