The lifetime of inexpensive bags of a sample of 25 bags has a standard deviation of 4.8 months assume the variable is normally distributed.

The lifetime of inexpensive bags of a sample of 25 bags has a standard deviation of 4.8 months assume the variable is normally distributed. use the chi-square distribution table to find any chi-square values to three decimal places. round your final answers to one decimal place. finding the 90% confidence interval for the variance and standard deviation is want I need help with please