Use the given information to find the number of degrees of freedom, the critical values X2L,and X2R the confidence interval estimate of sigma .

Use the given information to find the number of degrees of freedom, the critical values X2L,and X2R the confidence interval estimate of sigma 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 95% confidence; s= 0.24 mg.

Please show me a way to get the answer in Excel. Or way to set it up. I need a way to solve future problems.