In: Statistics and Probability
Use the given information to find the number of degrees of freedom, the critical values
chi Subscript Upper L Superscript 2χ2L
and
chi Subscript Upper R Superscript 2χ2R,
and the confidence interval estimate of
sigmaσ.
It is reasonable to assume that a simple random sample has been selected from a population with a normal distribution.
Platelet Counts of Women
9898%
confidence;
nequals=2424,
sequals=65.165.1.
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Solution :
Given that,
s = 65.1
s2 = 4238.01
2L
=
2
/2,df
= 41.638
2R
=
21 -
/2,df = 10.196
The 98% confidence interval for
is,
(n
- 1)s2 /
2
/2
<
<
(n - 1)s2 /
21 -
/2
23
* 4238.01 / 41.638 <
<
23 * 4238.01 / 10.196
48.38 <
< 97.78
(48.38 , 97.78)