12.1 Test of Two Variances
if δ0=1 then
Test statistic is :
12.3 The F Distribution and the F-Ratio
dfbetween = df(num) = k – 1
dfwithin = df(denom) = n – k
MSbetween =
MSwithin =
F =
- k = the number of groups
- nj = the size of the jth group
- sj = the sum of the values in the jth group
- n = the total number of all values (observations) combined
- x = one value (one observation) from the data
- = the variance of the sample means
- = the mean of the sample variances (pooled variance)