You used the statistical programs to calculate the correlations between TIPAMT and each of these 3 variables #PRTY, #EYECNT, #TRPS. The correlations are as follows .69, .73, -.14. How useful are these correlations? Select one: a. They are not very useful as the correlation between TIPAMT and other variables may vanish once they are all in one regression equation b. They are very useful are they show how TIPAMT is associated with some important variables