Question

To apply a hypothesis test, the contrast statistic must measure:
select one:
a) the difference between the sample and the H1
b) None of the above
c) The difference between the sample and the H0
d) the difference between H0 and H1.

Answer 1

This contrast is the difference between the means of groups 1 and 2 ignoring groups 3 and 4 (those latter two groups receive weights of 0). T h contrast is an estimate of the true population value I.

Ho: µ1 - µ2 = 0

It can also me written as
Ho: (1)µ1 + (-1)µ2 = 0T

Thus the null hypothesis of the two sample t-test is that the 1, -1 contrast on the two population means is equal to zero.

Contrast statistic t=estimate of population parameter ÷ st. dev. of sampling distribution

i.e t= I÷ standard error of I

Where, I is calculated by using difference between H0 and H1

And: d) the difference between H0 and H1