The probability that a kid who goes to the doctor has a sore throat given that he has a fever is 0.30 or 30%. Computed using conditional probability.
The probability of any event A given that event B has already taken place is found using the formula P(A|B) = P(A ∩ B)/P(B). This is known as conditional probability, where P(A ∩ B) is the probability of events A and B, and P(B) is the probability of event B.
In the question, we are given that 70% of kids who visit a doctor have a fever and 21% of kids have a fever and sore throats.
We are asked to find the probability that a kid who goes to the doctor has a sore throat given that he has a fever.
We suppose the event of going to the doctor while having a fever to be B, and going to a doctor while having a sore throat to be A.
We are given that 70% of kids who visit a doctor have a fever, that is, the probability of event B, P(B) = 70% = 0.7.
We are given that 21% of kids who visit a doctor have a fever and sore throats, that is, the probability of event A and event B, P(A ∩ B) = 21% = 0.21.
We are asked to find the probability that a kid who goes to the doctor has a sore throat given that he has a fever, that is, we are asked to find the conditional probability of event A, when event B has already taken place, that is, P(A|B).
By formula, we know that:
P(A|B) = P(A ∩ B)/P(B) = 0.21/0.70 = 0.30.
Thus, the probability that a kid who goes to the doctor has a sore throat given that he has a fever is 0.30 or 30%.
Learn more about conditional probability at
https://brainly.com/question/10739997
#SPJ4
