Dimes are minted with weights having a mean of 2.756 g and a standard deviation of 0.021 g. New equipment is being tested in an attempt to improve quality by reducing variation. A simple random sample of 35 dimes are obtained from those manufactured with the new equipment, and this sample has a standard deviation of 0.017 g.

Use the sample results to construct a 90% confidence interval of the standard deviation of the weights of dimes made with the new equipment.


I am so lost with this problem someone please help.