A sample of 10 FDA inspectors had the following consumption of paper (in pages) last month: 23, 31, 40, 55, 52, 34, 52, 67, 88, 92.

What is the best estimate ofpopulation standard deviation, and which one best describes the90%confidence interval (C.I.) for the mean paper consumption (in pages)? (You need refer to the table at the end of your textbook)

A. s (population standard deviation) = 23.24, 90% C.I.=[38.23, 67.92]

B. s (population standard deviation) = 23.24, 90% C.I.=[37.28, 68.32]

C. s (population standard deviation) = 23.24, 90% C.I.=[39.93, 66.87]

D. s (population standard deviation) = 42.47, 90% C.I.=[45.23, 61.92]

E. s (population standard deviation) = 42.47, 90% C.I.=[41.41, 65.41]