Since given : all row sums are same as each other and all diagonal sums and all column sums
mid row = 3.6 + 3 + 2.4 = 9
$\therefore$ a$_{11}$ + a$_{22}$ + a$_{33}$ = 9
9 – 2.3 – 3 = a$_{33}$ = 3.7
also, a$_{11}$ + a$_{21}$ = 5.9
$\therefore$ a$_{31}$ = 3.1
x = a$_{32}$ = 9 – 3.1 – 3.7 = 2.2
d)