Question

1800 families with 2 children were selected randomly and the following data were recorded:

No. of girls in a family	2	1	0
No. of families	700	850	250

Computer the probability of a family chosen at random having: 1 girl.

Answer 1

Total number of families
n(S) = 1800

Event = { 1 girl }
n(E) = 850
P(E) = ?

P(E) = `"n(E)"/"n(S)" = 850/1800 = 17/36`.