Use the given information to find the number of degrees of​ freedom, the critical values chi Subscript Upper L Superscript 2 and chi Subscript Upper R Superscript 2​, and the confidence interval estimate of sigma. It is reasonable to assume that a simple random sample has been selected from a population with a normal distribution.
Platelet Counts of Women 80​% ​confidence; nequals21​, sequals65.4.
dfequals

20 ​(Type a whole​ number.)
Part 2
chi Subscript Upper L Superscript 2equals

enter your response here
​(Round to three decimal places as​ needed.)
Part 3
chi Subscript Upper R Superscript 2equals

enter your response here
​(Round to three decimal places as​ needed.)
Part 4
The confidence interval estimate of sigma is

enter your response hereless thansigmaless than

enter your response here.
​(Round to one decimal place as​ needed.)