Question

Assume the sample is taken from a normally distributed population. Construct 80​% confidence intervals for​ (a) the population variance sigmasquared and​ (b) the population standard deviation sigma. 1.73

1.85

1.56

1.64

1.71

1.98

1.32

1.51

1.46

2.01

Answer 1

(a)Confidence Interval for Population Variance:

where, n: sample size=10
: sample variance=0.050446
: percentile value of the chi-square distribution with n-1 df.=9
0.20

(b) Confidence Interval for Population Standard Deviation:

where, n: sample size=10
: sample variance=0.050446
: percentile value of the chi-square distribution with n-1 df.=9
0.20

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