Question

The following sample of weights was taken from 8cookies off the assembly line. Construct the 95%

confidence interval for the population variance for all cookies that come off the assembly line. Round your answers to two decimal places.

9.6,10.2,10.3,9.2,9.5,10.1,9.2,9.4

Answer 1

	Weights (X)	X2
	9.6	92.16
	10.2	104.04
	10.3	106.09
	9.2	84.64
	9.5	90.25
	10.1	102.01
	9.2	84.64
	9.4	88.36
Total	77.5	752.19

n = 8

Here ,

n=8

degree of freedom = n - 1 = 8 - 1 =7

From table,

Now,

The confidence interval for the population variance is given by