13. I am trying to predict the weight of a newborn given some information about its mother and prenatal care. WT is the birth weight, it is the criterion. MWT is the mother's weight before getting pregnant, WTGN is how much weight the mother gained during pregnancy, SMK is how many cigarettes a day the mother smoked during pregnancy, and PRN is how far into the pregnancy the mother was when she began receiving prenatal care. Here is a correlation matrix of the correlations between pairs of variables. Use this matrix to answer the following question. In this matrix, what is the correlation between smokin and wei- ht ain? IEE_ WT MWT SMK WTGN PRN