Question

In a university 45 percent of whose students are boys and the remaining are girls, we select 23 persons. If we show the number of boys in sample with x and the number of girls in sample with y, write only the appropriate number instead of each question mark below: (Please be noticed that no additional calculation is needed)

a) p ( x > = 8 ) = ?
b) p ( x > = 8 ) = p ( x > ? )
c) p ( x > = 5 ) = p ( y < = ? )
d) p ( x < y ) + p ( x > y ) = ?
e) p ( x > = 5 ) = p ( y < = ?)