Fifteen specimens of human sera were tested comparatively for tuberculin antibody by two methods.

The logarithms of the titers obtained by the two methods were as follows:

Method A (X) B (Y)

3.31 4.09 2.41 3.84 2.72 3.65 2.41 3.20 2.11 2.97 2.11 3.22 3.01 3.96 2.13 2.76 2.41 3.42 2.10 3.38 2.41 3.28 2.09 2.93 3.00 3.54 2.08 3.14 2.11 2.76 Find the regression equation describing the relationship between the two variables, compute and test by both the F test and the t test.