There are 800 families with four children in each family. Assuming equal chance for every child to be a boy or a girl, the number of families expected to have children of both sexes is

Step-by-step solution

Given that 4 children in each family. Event of expected to have children of both sexes (= 1 2 ) ( ) Probability of children of both sexes ( aligned & =1-[P( all boys )+P (all girls) ] & =1- ( 1 2 )^4+ ( 1 2 )^4 & =1- ( 1 16 + 1 16 )=1- 1 8 = 7 8 aligned ) Hence, the probability for 800 families (= 7 8 800=700 )