\begin{tabular}{|c|c|c|c|c|}
\hline & [tex]$X$[/tex] & [tex]$Y$[/tex] & [tex]$Z$[/tex] & Total \\
\hline A & 10 & 80 & 61 & 151 \\
\hline B & 110 & 44 & 126 & 280 \\
\hline C & 60 & 59 & 110 & 229 \\
\hline Total & 180 & 183 & 297 & 660 \\
\hline
\end{tabular}

Which statement is true about whether Z and B are independent events?

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

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

C. [tex]$Z$[/tex] and [tex]$B$[/tex] are not independent events because [tex]$P(Z \mid B) \neq P(Z)$[/tex].

D. [tex]$Z$[/tex] and [tex]$B$[/tex] are not independent events because [tex]$P(Z \mid B) \neq P(B)$[/tex].



Answer :

To determine whether [tex]\( Z \)[/tex] and [tex]\( B \)[/tex] are independent events, we need to compare [tex]\( P(Z) \)[/tex] and [tex]\( P(Z \mid B) \)[/tex]. Let's proceed step by step:

1. Calculate [tex]\( P(Z) \)[/tex]:
[tex]\[ P(Z) = \frac{\text{Total number of \( Z \) outcomes}}{\text{Total number of outcomes}} \][/tex]
Given:
[tex]\[ \text{Total number of } Z \text{ outcomes} = 297 \][/tex]
[tex]\[ \text{Total number of outcomes} = 660 \][/tex]

Thus:
[tex]\[ P(Z) = \frac{297}{660} \approx 0.45 \][/tex]

2. Calculate [tex]\( P(B) \)[/tex]:
[tex]\[ P(B) = \frac{\text{Total number of \( B \) outcomes}}{\text{Total number of outcomes}} \][/tex]
Given:
[tex]\[ \text{Total number of } B \text{ outcomes} = 280 \][/tex]
[tex]\[ P(B) = \frac{280}{660} \approx 0.42424242424242425 \][/tex]

3. Calculate [tex]\( P(Z \mid B) \)[/tex]:
[tex]\[ P(Z \mid B) = \frac{\text{Number of outcomes that are both \( Z \) and \( B \)}}{\text{Total number of \( B \) outcomes}} \][/tex]
Given:
[tex]\[ \text{Number of outcomes that are both } Z \text{ and } B = 126 \][/tex]
[tex]\[ \text{Total number of } B \text{ outcomes} = 280 \][/tex]

Thus:
[tex]\[ P(Z \mid B) = \frac{126}{280} \approx 0.45 \][/tex]

4. Compare [tex]\( P(Z) \)[/tex] and [tex]\( P(Z \mid B) \)[/tex]:
[tex]\[ P(Z) = 0.45 \][/tex]
[tex]\[ P(Z \mid B) = 0.45 \][/tex]

Since:
[tex]\[ P(Z) = P(Z \mid B) \][/tex]

We can conclude that [tex]\( Z \)[/tex] and [tex]\( B \)[/tex] are independent events because the probability of [tex]\( Z \)[/tex] occurring is the same whether or not [tex]\( B \)[/tex] occurs.

Therefore, the true statement is:
[tex]\[ \text{Z and B are independent events because } P(Z \mid B) = P(Z). \][/tex]