A survey finds that [tex]$48\%$[/tex] of people identify themselves as fans of professional football, [tex]$12\%$[/tex] as fans of car racing, and [tex]$9\%$[/tex] as fans of both professional football and car racing. Let event [tex]$F$[/tex] be choosing a person who is a fan of professional football and let event [tex]$C$[/tex] be choosing a person who is a fan of car racing.

Which statements are true? Select three options.

A. [tex]$P(F \mid C)=0.75$[/tex]

B. [tex]$P(C \mid F)=0.25$[/tex]

C. [tex]$P(C \cap F)=0.09$[/tex]

D. [tex]$P(C \cap F)=P(F \cap C)$[/tex]

E. [tex]$P(C \mid F)=P(F \mid C)$[/tex]



Answer :

Let's break down the problem step-by-step to determine which statements are true.

Given:
1. [tex]\(P(F) = 0.48\)[/tex] (probability that a person is a fan of professional football)
2. [tex]\(P(C) = 0.12\)[/tex] (probability that a person is a fan of car racing)
3. [tex]\(P(F \cap C) = 0.09\)[/tex] (probability that a person is a fan of both professional football and car racing)

### Calculate the Conditional Probabilities

First, let's determine the conditional probability [tex]\(P(F \mid C)\)[/tex]:

[tex]\[ P(F \mid C) = \frac{P(F \cap C)}{P(C)} \][/tex]

Substituting the given values:

[tex]\[ P(F \mid C) = \frac{0.09}{0.12} = 0.75 \][/tex]

So, [tex]\(P(F \mid C )=0.75\)[/tex] is true.

Next, let's calculate [tex]\(P(C \mid F)\)[/tex]:

[tex]\[ P(C \mid F) = \frac{P(F \cap C)}{P(F)} \][/tex]

Substituting the given values:

[tex]\[ P(C \mid F) = \frac{0.09}{0.48} = 0.1875 \][/tex]

So, [tex]\(P(C \mid F)=0.25\)[/tex] is false.

### Verification of Probabilities and Equalities

- We are given [tex]\(P(F \cap C)=0.09\)[/tex], so this statement [tex]\(P(C \cap F)=0.09\)[/tex] is true.

- From the definition of intersection, we know [tex]\(P(C \cap F) = P(F \cap C)\)[/tex]. This is always true for any events [tex]\(F\)[/tex] and [tex]\(C\)[/tex], thus the statement [tex]\(P(C \cap F) = P(F \cap C)\)[/tex] is true.

- Finally, considering the symmetry of conditional probabilities, [tex]\(P(C \mid F) = P(F \mid C)\)[/tex] is generally false unless [tex]\(P(F) = P(C)\)[/tex], which is not given here.

### Summary of True Statements

The true statements, therefore, are:
1. [tex]\(P(F \mid C )=0.75\)[/tex]
2. [tex]\(P(C \cap F)=0.09\)[/tex]
3. [tex]\(P( C \cap F )=P(F \cap C )\)[/tex]

Thus, the selected three options should be:

1. [tex]\(P(F \mid C)=0.75\)[/tex]
2. [tex]\(P(C \cap F)=0.09\)[/tex]
3. [tex]\(P(C \cap F) = P(F \cap C)\)[/tex]

These three options are correct based on the given information and calculations.