Table- represent the time study observation for five elements which together form an operation that is performed on a job. a. Based on the observations, what is the standard time for the operation providing an allowance of 10% of job time? [3 Marks] b. How many observations are needed for each element to estimate the mean times within 10% of its true value with a 95% confidence? [2 Marks] c. Which element is the bottleneck for the operation? [1 Mark]

Performance Observations (minutes per cycle) Element Rating 1 2 3 4 5 A 70% 0.83 0.87 0.78 0.82 0.85 B 90% 2.2 2.5 2.0 1.9 2.1 C 130% 1.20 1.17 1.16 1.22 1.24 D 112% 4.3 4.0 3.5 4.8 4.0 E 80% 0.58 0.53 0.52 0.59 0.60 Table-2: Time Study Observations for 5-Elements which Make Up an Operation 6 1.32 2.0 1.15 4.3 0.54