Question

Loan Processing times are being monitored at a local company. Samples of six observations each have been taken, and the results are listed. Using Factors from Table 10.3, determine lower and upper control limits for a a mean chart Sample Number

Sample Number 1        2         3         4         5

-------------       41       53       40       58       43

-------------       49       38       57       49       60

-------------       44       48       53       52       47

-------------       43       50       40       37       60

-------------       45       53       44       47       42

-------------       48       62       41       50       47

Question 6 options:

	38.705 , 57.361
	39.585 , 56.481
	27.617 , 68.449
	37.825 , 58.241
	None of the Above

Answer 1

Hey I have calculated using excel.

I Have calculated using both range and standard deviation as estimates of population standard deviation.

options given are very close so its difficult to decide as it is not mentioned which methodology is used. I have used both SD and range. You can decide on your own.

formula used are standard for control chart for mean

CL(control limit is just the grand mean of all sample mean.

these are formula used see LCL and UCL:

this is the table of constants: