I have two sets of data that are significantlly different based on t-test.

The number in the data is the sum of three independent variables. For example, A=x +y +z

Since I know that the A values from one group is significantlly different comparing the A values from the other group, I would like to know which components of A (x, y or z?) contributes to the significance and how much the contribution is.

For example, the x values and z values between the two groups may not be significantly different, but the y-values are significantly different, which make the A values significantly different. So the contribution is mainly from y.