Process time at a workstation is monitored using sample mean and range control charts. Six samples of n = 8 observations have been obtained and the sample means and ranges computed (in minutes):

Sample	Mean	Range
1	3.24	0.52
2	3.12	0.52
3	3.13	0.54
4	3.03	0.45
5	3.14	0.42
6	3.10	0.45

a. Using the factors in Table 10-3, determine the upper and lower limits for sample mean and range control charts. (Round the intermediate calculations to 2 decimal places. Round the final mean answers to 2 decimal places. Round the final range answers to 3 decimal places.)

	UCL	LCL
Mean
Range

b. Is the process in control?

multiple choice

• Yes

• No