Question

In order to construct a confidence interval for the population variance, a random sample of n observations is drawn from a normal population. Use this information to find χ²_α/2,df and χ²_1-α/2,df under the following scenarios. Use Table 3. (Round your answers to 3 decimal places.)

  

		χ2α/2,df	χ21-α/2,df
a.	A 95% confidence level with n = 12.
b.	A 95% confidence level with n = 29.
c.	A 99% confidence level with n = 12.
d.	A 99% confidence level with n = 29.

Answer 1

Using Excel we find, critical values for the following cases,

a) A 95% confidence level with n = 12

df = 12 - 1 = 11

b) A 95% confidence level with n = 29

df = 29 - 1 = 28

c) A 99% confidence level with n = 12

df = 12 - 1 = 11

d) A 99% confidence level with n = 29

df = 29 - 1 = 28