Answer:
Option D -
Step-by-step explanation:
Given : The manufacturer measures 19 randomly selected dowels and finds the standard deviation of the sample to be s=0.16.
To find : The 95% confidence interval for the population standard deviation sigma?
Solution :
Number of sample n=19
The degree of freedom is Df=n-1=19-1=18
The standard deviation of the sample is s=0.16
Applying chi-square table to find critical value,
Upper critical value of is
Lower critical value of is
Lower limit of the 95% confidence interval for the population variance
Upper limit of the 95% confidence interval for the population variance
So, The 95% confidence interval for the population variance is [0.0146, 0.0560]
Now, The 95% confidence interval for the population standard deviation is
or
Therefore, Option D is correct.
The 95% confidence interval for the population standard deviation is