Answer:
The probability that a fan is waving a banner given that the fan is cheering for team A is 0.25.
Explanation:
The percentage of fans cheering for team A is, 80%.
The percentage of fans waving banners and cheering from team A is, 20%.
The probability that a fan is cheering is: P (C) = 0.80.
The probability that a fan is waving banners and cheering is:
P (W ∩ C) = 0.20.
The conditional probability of an event X provided that another event A has already occurred is:
![P(X|A)=(P(X\cap A))/(P(A))](https://img.qammunity.org/2021/formulas/mathematics/high-school/dd6u00swpg5nml2xotwb6gw7klbfmlbfws.png)
Compute the conditional probability that a fan is waving a banner given that the fan is cheering for team A as follows:
![P(W|C)=(P(W\cap C))/(P(C))=(0.20)/(0.80)= 0.25](https://img.qammunity.org/2021/formulas/mathematics/high-school/t5uz4uavc1w3wg0g0sraz0px1f8fru06st.png)
Thus, the probability that a fan is waving a banner given that the fan is cheering for team A is 0.25.