Determine the value of \( c \) and the covariance and correlation for the joint probability mass function \( f(x, y) \) \( =c(x+y) \) for \( x=1,2,3 \) and \( y=1,2,3 \).
Statistical Tables and Charts
Part 1
\( c= \) \( \square \)
Give exact answer in form of fraction.