Question

Determine the critical values for the confidence interval for the population standard deviation from the given values. Round your answers to three decimal places.

N = 18 and a =.01

Lower = ? and Upper = ?

Answer 1

Solution :

Given that,

n = 18

Degrees of freedom = df = n - 1 = 18 - 1 = 17

At 99% confidence level the ² value is ,

= 0.01

/ 2 = 0.01 / 2 = 0.005

1 - / 2 = 1 - 0.005 = 0.995

²_L = ²_/2,df = 35.718

²_R = ²_{1 - /2,df} = 5.697