Question

HELP GRADE 4 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1

(1) Total No of families = 1500

Total No of families with 2 girls = 475

Probability of family being chosen at random having 2 girls = 475/1500 = P1 = 19/60

(2) Total No of families = 1500

Total No of families with 1 girl = 814

Probability of family being chosen at random having 1 girl = 814/1500 = P2 = 407/750

(3) Total No of families = 1500

Total No of families with no girl = 211

Probability of family being chosen at random having no girls = P3 = 211/1500

(4) P1 + P2 +P3

=19/60 + 407/750 + 211/1500

= 475 + 814 + 211/1500

=1500/1500

=1

Yes, the sum of there Probabilities does add up to 1

Answer 2

i) = num of families having 2 girls/ total num of families
= 475/1500
=19/60
ii) = num of families having 1 girl/ total num of families
= 814/1500
iii) = num of families having no girl/ total num of families
= 211/1500
iv) 475/1500 + 814/1500 + 211/1500 = 1