3. Sample size ( 10 marks)

The operations manager from Q6 wants to make sure the right sample size was used to collect the observations and calculate the standard time.

The companys owner will be satisfied within an accuracy 2% in the time estimates but wants to be 99% confident.

Determine if the sample size of 10 that was used was sufficient to meet the owners expectations. Describe your findings. Hint: You will have to recall how to calculate the standard deviation from the observations in Q6.

ANSWER TO QUESTION 6:

OBSERVED TIME 7.176

NORMAL TIME 7.176X0.95

STANDARD TIME 7.101

6. Standard Time ( 5 marks) A large cable company received a shipment of audio video cables with the wrong connectors. The error was made by the cable company's specifications provided to the overseas supplier. The operations manager calculates that it would be cheaper to manually change the connectors rather than the supplier re-doing or fixing the cables. The manager observes the first set of workers pulled aside to change the cables and from these observations will set a standard time. The observations are as follows for workers to each change the connectors on sets of 20 cables. Time (min) Observation The manager will use a performance rating factor of .95 and an allowance factor of .04. 1 7.17 2 7.23 3 6.98 4 7.05 5 7.54 6 7.33 7 7.11 8 7.27 9 7.09 10 6.99