### Determining if Two Events Are Independent

The two-way table shows the results of a recent study on the effectiveness of the flu vaccine. Let [tex]\(N\)[/tex] be the event that a person tested negative for the flu, and let [tex]\(V\)[/tex] be the event that the person was vaccinated.

[tex]\[
\begin{tabular}{|c|c|c|c|}
\cline {2-4} \multicolumn{1}{c|}{} & Pos. & Neg. & Total \\
\hline Vaccinated & 465 & 771 & 1,236 \\
\hline \begin{tabular}{c} Not \\ Vaccinated \end{tabular} & 485 & 600 & 1,085 \\
\hline Total & 950 & 1,371 & 2,321 \\
\hline
\end{tabular}
\][/tex]

Answer the questions to determine if events [tex]\(N\)[/tex] are independent. Round your answers to the nearest hundredth.

[tex]\[ P(N \mid V ) = \square \][/tex]

[tex]\[ P(N) = \square \][/tex]

Are events [tex]\(N\)[/tex] and [tex]\(V\)[/tex] independent events? Yes or No: [tex]\(\square\)[/tex]



Answer :

To determine if events [tex]\( N \)[/tex] (testing negative for the flu) and [tex]\( V \)[/tex] (being vaccinated) are independent, we need to compare [tex]\( P(N \mid V) \)[/tex] and [tex]\( P(N) \)[/tex]. If these probabilities are equal, then the events are considered independent. Otherwise, they are dependent.

### Step-by-step Solution:

1. Calculate [tex]\( P(N \mid V) \)[/tex]:
- This is the conditional probability of testing negative for the flu given that a person was vaccinated.
- From the table, the number of people who were vaccinated and tested negative is 771.
- The total number of vaccinated people is 1,236.

[tex]\[ P(N \mid V) = \frac{\text{Number of vaccinated people who tested negative}}{\text{Total number of vaccinated people}} = \frac{771}{1236} \][/tex]

[tex]\[ P(N \mid V) \approx 0.62 \][/tex]

2. Calculate [tex]\( P(N) \)[/tex]:
- This is the probability of testing negative for the flu out of the entire population.
- From the table, the total number of people who tested negative is 1,371.
- The grand total number of people in the study is 2,321.

[tex]\[ P(N) = \frac{\text{Total number of people who tested negative}}{\text{Total number of people in the study}} = \frac{1371}{2321} \][/tex]

[tex]\[ P(N) \approx 0.59 \][/tex]

3. Determine if events [tex]\( N \)[/tex] and [tex]\( V \)[/tex] are independent:
- Compare [tex]\( P(N \mid V) \)[/tex] and [tex]\( P(N) \)[/tex].
- If [tex]\( P(N \mid V) = P(N) \)[/tex], then the events are independent.
- Here, [tex]\( P(N \mid V) \approx 0.62 \)[/tex] and [tex]\( P(N) \approx 0.59 \)[/tex], which means they are not equal.

Therefore:

[tex]\[ \text{Are \( N \) and \( V \) independent?} \quad \text{No} \][/tex]

### Summary
[tex]\[ P(N \mid V) \approx 0.62 \][/tex]
[tex]\[ P(N) \approx 0.59 \][/tex]
[tex]\[ \text{Are events \( N \) and \( V \) independent?} \quad \text{No} \][/tex]

So, the values filled in the boxes would be:
- [tex]\( P(N \mid V) = 0.62 \)[/tex]
- [tex]\( P(N) = 0.59 \)[/tex]
- Are events [tex]\( N \)[/tex] and [tex]\( V \)[/tex] independent? No