Question

If n = 81, find the critical values X2/L and X 2/R for a confidence level of 99%.

Answer 1

Solution :

Given that,

n = 81

At 99% confidence level the z is ,

  = 1 - 99% = 1 - 0.99 = 0.01

/ 2 = 0.01 / 2 = 0.005

1 - / 2 = 1 - 0.005 = 0.995

df = n - 1 = 81 - 1 = 80

Using ² table,

²_L = ² _{/ 2} = ²_0.005 = 116.321

²_R = ²_{1 - / 2} = ²_0.995 = 51.172