qThere are two samples, each has six measurements
of wind speed. The first
sample measures a wind speed variance of 10 (m/sec)2. The
second sample
measures a 6 (m/sec)2 variance.
Are these two variance significantly
different?
q
qAnswer: (1) Selected a 95% significance level (a =
0.05)
q
(2) H0: s1 = s2
q H1: s1 ¹ s2
q
(3) Use F-test
q F = 10/6 =
1.67
q
(4) This is a two-tailed test. So choose the 0.025 significance
areas.
q For n1 = n1 = 6-1=5, F0.975=7.15.
q
(5) Since F< F0.975, the null
hypothesis can not be rejected.
q
(6) Variance from these two samples are not significantly different.