Below are sets of summary statistics for two sets of samples. You want to compare the variances. How can you compare them?
Mean |
Variance |
Range |
Sample size |
|
Set 1 |
43.6 |
10.2 |
23-62 |
17 |
Set 2 |
31.2 |
5.7 |
25-39 |
26 |
we can use f test to compare the two variance
let Ho:
H1:
using minitab>stat>basic stat> two variance
Test and CI for Two Variances
Method
Null hypothesis σ(First) / σ(Second) = 1
Alternative hypothesis σ(First) / σ(Second) ≠ 1
Significance level α = 0.05
F method was used. This method is accurate for normal data only.
Statistics
95% CI for
Sample N StDev Variance StDevs
First 17 3.194 10.200 (2.379, 4.861)
Second 26 2.387 5.700 (1.872, 3.296)
Ratio of standard deviations = 1.338
Ratio of variances = 1.789
95% Confidence Intervals
CI for
CI for StDev Variance
Method Ratio Ratio
F (0.866, 2.163) (0.751, 4.677)
Tests
Test
Method DF1 DF2 Statistic P-Value
F 16 25 1.79 0.186
since p value is large so we accept H0 and can conclude that the two variance are same
Below are sets of summary statistics for two sets of samples. You want to compare the...
Below are sets of summary statistics for two sets of samples. You want to compare the variances. How can you compare them? Mean Variance Range Sample size Set 1 43.6 10.2 23-62 17 Set 2 31.2 5.7 25-39 26
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