In: Statistics and Probability
You randomly select and weigh 23samples of an allergy medication. The sample standard deviation is 1.56milligrams. Assuming the weights are normally distributed, construct 95% confidence intervals for the population variance and standard deviation.Please interpret your result.
Solution :
Given that,
n = 23
df = 22
2R = 2/2,df = 36.781
2L = 21 - /2,df = 10.982
The 95% confidence interval for 2 is,
(n - 1)s2 / 2/2 < 2 < (n - 1)s2 / 21 - /2
22 * 1.562 / 36.781 < 2 < 22 * 1.562 / 10.982
1.2065 < 2 < 2.2079
(1.2065 , 2.2079 , )