A medical facility does MRIs for sports injuries. Occasionally a test yields inconclusive results and must be repeated. Using the following sample data and n = 194.

	SAMPLE
	1	2	3	4	5	6	7	8	9	10	11	12	13
Number of retests	2	1	1	0	2	2	2	0	2	7	4	1	2

a.	Determine the upper and lower control limits for the fraction of retests using two-sigma limits. (Do not round intermediate calculations. Round your finalanswers to 4 decimal places. Leave no cells blank - be certain to enter "0" wherever required.)

UCL
LCL

b.

Is the process in control?

Yes

No

HINT-Calculate: control limits p_no. of sigma limits*(p_(1-p_)/n). p_=no. of retests/no. of samples*n

After a number of complaints about its directory assistance, a telephone company examined samples of calls to determine the frequency of wrong numbers given to callers. Each sample consisted of 117 calls.

	SAMPLE
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Number of errors	2	3	5	3	2	6	4	2	5	10	3	3	5	4	6	5

a.	Determine 95 percent limits. (Do not round your intermediate calculations.Round your final answers to 3 decimal places.)

UCL
LCL

b.	Is the process stable (i.e., in control)?
	Yes No