Use the given information to find the number of degrees of​ freedom, the critical values χ2L and χ2R​, and the confidence interval estimate of σ. It is reasonable to assume that a simple random sample...

Use the given information to find the number of degrees of​ freedom, the critical values χ2L and χ2R​, and the confidence interval estimate of σ. It is reasonable to assume that a simple random sample has been selected from a population with a normal distribution. Nicotine in menthol cigarettes 99​% ​confidence; n=20​, s=0.26 mg.

df=(whole number)

x2L=(3 decimal places)

x2R=(3 decimal places)

Confidence interval estimate of σ=