Researchers at the University of Pennsylvania School of Medi

Researchers at the University of Pennsylvania School of Medicine have determined that children under 2 years old who sleep with the lights on have a 35% chance of becoming myopic before they are 16. Children who sleep in darkness have a 29% probability of becoming myopic. A survey indicates that 22% of children under 2 sleep with some light on. Find the probability that a random child under 2 will become myopic before reaching 16 years old.

Probability=

Solution

probability of children who sleeps with lights on and become myopic P(A) = 0.35

probability of children who sleeps in darkness and become myopic P(B)= 0.29

percentage of children keeps their lights on, during sleeping P(C)= 0.22

percentage of children keep their lights off , during sleeping P(D)= 0.78

probability of random child become myopic

=P(C) * P(A) + P(D) * P(B)

= 0.22 * 0.35 + 0.78 * 0.29

= 0.3032 or 30.32%