a)Colonial Electric is a large company that produces lightbulbs and other electrical appliances. One particular lightbulb is supposed to have an average life of about 1,000 hours before it burns out. Periodically the company will test 5 of these and measure the average time before these burn out.The following table gives the result of 10 such samples:

Sample	1	2	3	4	5	6	7	8	9	10
Mean	979	1087	1080	934	1072	1007	952	986	1063	958
Range	50	94	57	65	135	134	101	98	145	84

1.What is the overall average of these means? What is the average range?

2.What are the upper and lower control limits for a 99.7% control chart for the mean?

3.Does this process appear to be in control? Explain.

4.Explain why a process can be out of control even though all the samples fall within the upper and lower control limit