N: salary of nurses
T: salary of teachers

You are testing

H0 : E(T) = E(N)
H1 : E(T) > E(N), E(T) - E(N) > 0

with 1% significance (or 99% confidence).



Some parts are in portuguese. But i think you cant get it anyway. (GL is Degrees of Freedom).

You assume variances are different, because the populations are of small dimension, and you'd have to estimate the common variance.

There's another way which is to setup an interval of confidence of 99%.

You do it for the difference of the expected values.



GL is degrees of freedom
NA is size of population A
SA is the estimator of the variance of population A (since it is of small dimension we have to use the estimator, which you calculate the same way as the variance)
alpha on this case will be 0.01

If the interval goes from positive values to positives values [+,+] you know the expected value of the 1st is bigger than the second, and vice versa. Otherwise you can't conclude anything.

For the p value, you have to go with the first method, so this second one would be just to answer the first part of the question.