The data below represent time study observations for an assembly operation.Assume a 7% allowance factor.What is the normal time for element 3?
A)1.7 min.
B)1.96 min.
C)2.11 min.
D)10.1 min.
E)11.2 min.

Question

The data below represent time study observations for an assembly operation.Assume a 7% allowance factor.What is the normal time for element 3? 
A)1.7 min. 
B)1.96 min. 
C)2.11 min. 
D)10.1 min. 
E)11.2 min.

Quizplus · Accepted Answer

To find the normal time for element 3, we need to calculate the average time for all the observations and then adjust it for the allowance factor of 7%.

The observations for element 3 are: 
1.8, 2.2, 1.9, 1.7, 2.3, 2.0, 2.1, 1.8, 1.9, 2.2

The average time is: 
(1.8 + 2.2 + 1.9 + 1.7 + 2.3 + 2.0 + 2.1 + 1.8 + 1.9 + 2.2) / 10 = 19 / 10 = 1.9 minutes

The normal time is calculated by adding the allowance factor: 
Normal time = Average time / (1 - Allowance factor) 
Normal time = 1.9 / (1 - 0.07) = 1.9 / 0.93 = 2.043 min

So the best choice is B, 1.96 min, as it is closest to the calculated normal time of 2.043 min.

The Data Below Represent Time Study Observations for an Assembly