Experience the convenience of getting your questions answered at IDNLearn.com. Whether your question is simple or complex, our community is here to provide detailed and trustworthy answers quickly and effectively.

Alejandro surveyed his classmates to determine who has ever gone surfing and who has ever gone snowboarding. Let [tex]$A$[/tex] be the event that the person has gone surfing, and let [tex]$B$[/tex] be the event that the person has gone snowboarding.

[tex]\[
\begin{tabular}{|c|c|c|c|}
\hline & \begin{tabular}{c}
Has \\
Snowboarded
\end{tabular} & \begin{tabular}{c}
Never \\
Snowboarded
\end{tabular} & Total \\
\hline Has Surfed & 36 & 189 & 225 \\
\hline Never Surfed & 12 & 63 & 75 \\
\hline Total & 48 & 252 & 300 \\
\hline
\end{tabular}
\][/tex]

Which statement is true about whether [tex]$A$[/tex] and [tex]$B$[/tex] are independent events?

A. [tex]$A$[/tex] and [tex]$B$[/tex] are independent events because [tex]$P(A \mid B) = P(A) = 0.16$[/tex].

B. [tex]$A$[/tex] and [tex]$B$[/tex] are independent events because [tex]$P(A \mid B) = P(A) = 0.75$[/tex].

C. [tex]$A$[/tex] and [tex]$B$[/tex] are not independent events because [tex]$P(A \mid B) = 0.16$[/tex] and [tex]$P(A) = 0.75$[/tex].

D. [tex]$A$[/tex] and [tex]$B$[/tex] are not independent events because [tex]$P(A \mid B) = 0.75$[/tex] and [tex]$P(A) = 0.16$[/tex].


Sagot :

To determine whether the events [tex]\( A \)[/tex] (a student has gone surfing) and [tex]\( B \)[/tex] (a student has gone snowboarding) are independent, we'll check if [tex]\( P(A \mid B) = P(A) \)[/tex].

Given data:

- Total number of students surveyed: [tex]\( 300 \)[/tex]
- Students who have gone surfing ([tex]\( A \)[/tex]): [tex]\( 225 \)[/tex]
- Students who have gone snowboarding ([tex]\( B \)[/tex]): [tex]\( 48 \)[/tex]
- Students who have gone both surfing and snowboarding ([tex]\( A \cap B \)[/tex]): [tex]\( 36 \)[/tex]

First, we'll calculate the probabilities:

1. Probability that a student has gone surfing [tex]\( P(A) \)[/tex]:
[tex]\[ P(A) = \frac{\text{Number of students who have gone surfing}}{\text{Total number of students}} = \frac{225}{300} \][/tex]

2. Probability that a student has gone snowboarding [tex]\( P(B) \)[/tex]:
[tex]\[ P(B) = \frac{\text{Number of students who have gone snowboarding}}{\text{Total number of students}} = \frac{48}{300} \][/tex]

3. Probability that a student has gone surfing given that they have gone snowboarding [tex]\( P(A \mid B) \)[/tex]:
[tex]\[ P(A \mid B) = \frac{\text{Number of students who have gone both surfing and snowboarding}}{\text{Number of students who have gone snowboarding}} = \frac{36}{48} \][/tex]

Now, substituting the values:

1. Calculating [tex]\( P(A) \)[/tex]:
[tex]\[ P(A) = \frac{225}{300} = 0.75 \][/tex]

2. Calculating [tex]\( P(B) \)[/tex] (though not directly needed):
[tex]\[ P(B) = \frac{48}{300} \][/tex]

3. Calculating [tex]\( P(A \mid B) \)[/tex]:
[tex]\[ P(A \mid B) = \frac{36}{48} = 0.75 \][/tex]

Since [tex]\( P(A \mid B) = P(A) = 0.75 \)[/tex], the events [tex]\( A \)[/tex] and [tex]\( B \)[/tex] are indeed independent.

Thus, the correct statement is:
[tex]\( A \)[/tex] and [tex]\( B \)[/tex] are independent events because [tex]\( P(A \mid B) = P(A) = 0.75 \)[/tex].

So, the correct answer is:
[tex]\( A \)[/tex] and [tex]\( B \)[/tex] are independent events because [tex]\( P(A \mid B) = P(A) = 0.75 \)[/tex].