Question

A meat packaging plant uses a machine that packages ground chuck in three pound portions. A sample of 62 packages of ground chuck has a variance of 0.10. Construct the 98% confidence interval to estimate the variance of the weights of the packages prepared by the machine. Round your answers to two decimal places.

Answer 1

df = n - 1 = 62 - 1 = 61

Chi-square critical value at 0.02 level with 61 df = L = 38.273 , R = 89.591

98% confidence interval for is

(n-1) S² / R < < (n-1) S² / L

(62 - 1) * 0.10 / 89.591 < < (62-1) * 0.10 / 38.273

0.07 < < 0.16

98% CI is ( 0.07 , 0.16 )