1500 families with 2 children were selected randomly and the following data were recorded:
Compute the probability of family, chosen at random, having
(i) 2 girls, (ii)1 girl, (iii) No girl.
Also check whether the sum of these probabilities is 1.
(i) P (a family having 2 girls) = Number of families having 2 girls/Total number of families
= 475/1500 = 19/60
(ii) P (a family having 1 girl) = Number of families having 1 girl/Total number of families
= 814/1500 = 407/750
(iii) P (a family having no girl) = Number of families having no girl/Total number of families
Sum of probabilities = 475/1500 + 814/1500 + 211/1500 = 1500/1500 = 1