A quality control engineer pulls 9 bearings at random from an assembly line, and
ID: 645417 • Letter: A
Question
A quality control engineer pulls 9 bearings at random from an assembly line, and measures the diameter of each one. The measurements are 3.17, 3.21, 3.16, 3.15, 3.18, 3.22, 3.15, 3.16, and 3.19 mm.
(a) Estimate the population mean and its confidence interval for 95% confidence level. For consistency, give your answer to three decimal places to the right of the decimal point.
(b) Estimate the population standard deviation and its confidence interval for 95% confidence level. For consistency, give your answer to three decimal places to the right of the decimal point.
Explanation / Answer
(a) Population mean = 3.176
(b) Standard Deviation = 0.024