Use the One-Standard-Deviation Chi-Square Interval Procedure to Obtain the Specified $10.8$

Multiple Choice

Use the one-standard-deviation chi-square interval procedure to obtain the specified confidence interval for thepopulation standard deviation Ϭ. Assume that the population has a normal distribution.
-The mean replacement time for a random sample of 20 washing machines is $10.8$ years and the standard deviation is $2.7$ years. Construct a $99 \%$ confidence interval for the standard deviation, $\sigma$ , of the replacement times of all washing machines of this type.

A) $1.8$ to $5.1 \mathrm { yr }$
B) $1.9$ to $5.7 \mathrm { yr }$
C) $2.0$ to $4.3 \mathrm { yr }$
D) $1.9$ to $4.5 \mathrm { yr }$