Q.1 You want to establish control limits on your chart with a certain confidence level. You are using a z-value of 1.96. What percentage confidence interval is implied by this z-value?

Q.2 You want to establish control limits on your chart with a certain confidence level. What z-value do you need to obtain a 99.73% confidence interval?

Use this data Set

Observation	Measurement	Measurement	Measurement
1	63	60	84
2	60	48	86
3	59	83	34
4	96	78	55
5	75	48	89
6	37	81	78
7	94	76	89
8	70	93	80
9	66	61	68
10	75	25	63
11	60	103	61
12	76	81	110
13	69	76	67
14	84	81	56
15	76	65	84