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Question 4 [25 Marks a. In conducting time study, a work study officer has observed time taken by a job for 5 repetitive cycles as follows: 8 min, 7.5 min, 8.5 min 8.2 min, 8.3 min. Calculate how many observations are to be taken to determine the standard time for 5% accuracy and 95% confidence limit. (12 marks) b. Three repetitions of a certain work cycle has been time studied for arriving at a time standard for an assembly operation conducted in a manual assembly line. The operation has been divided into three work elements for the purpose of time study and each element has been separately timed using a stopwatch. Determine the standard cycle time for the operation assuming that an allowance of 15% is applicable. Use the details in the Table 04. Table Q4 Work Element number 1 Observed time (min) 1.22 1.19 1.20 110 2 2.57 2.58 2.62 90 3 0.47 0.49 0.32 100 Performance rating on 100 percent scale (13 marks)