Job No. 674 on an assembly line has been observed to have a mean time often hours, with a standard deviation of one hour. This information was collected by the workstudy department during the past year. During a week the following times were observed for three operators:

Job.No.A674 MrA MrB MrC Times hr hr hr 10 11 12 13 12 10 8

7 13 14 10 12

(i) Do you consider any of the deviations from the mean time to be significant and worth investigating?

(ii) What time should the firm adopt as its standard?