Intervention program of 10 weeks for women with depression and a three year folllow up. study has intervention group and control group - was intervention successful .
At the end of 10 week - here is the data.
Mean(int) 5.03, S = 1.01, n = 135
Mean (con) = 4.61, S = 1.13, n = 130

calculated it using T tests

t = mean(i) - mean(c)/sqrt [ (s^2(i)/n(i) + ( s^2(c)/n(c))]

So i understand we have two independent samples. we have two different sample sizes, why arent we using independent sample t test and pooling variances.?