The university's union executive surveyed its members to determine what the members felt were the important issues to be discussed during forthcoming negotiations with management. Results showed that 72% felt that job security was an important issue, while 55% felt that salary/benefits were important. Of those who felt that salary/benefits were an important issue, 87% also felt that job security was important.

(i) What percentage of the members felt that job security and salary/benefits were important?

(ii) What percentage of the members felt that at least one of these issues was important?

(iii) Is the importance attached to these two issues independent?

(iv) Of those who felt that job security was an important issue, what proportion felt that salary/benefits were important?