In: Statistics and Probability
the standard deviation of the diameter of 28 oranges was 0.34 inch. find the 99% confidence interval of the true standard deviation of the diameter of the orages.
Solution :
Given that,
s = 0.34
s2 = 0.1156
2L
=
2
/2,df = 49.645
2R
=
21 -
/2,df = 11.808
The 99% confidence interval for
is,
(n
- 1)s2 /
2
/2 <
<
(n - 1)s2 /
21 -
/2
27
* 0.1156 / 49.645 <
<
27 * 0.1156 / 11.808
0.25 <
< 0.51
(0.25 , 0.51)