Select the correct answer.

The results from a test to detect the presence of a nutrient in a soil sample are shown in the table.

[tex]\[
\begin{array}{|l|c|c|c|}
\hline & \text{Test is positive} & \text{Test is negative} & \text{Total} \\
\hline \text{Contains nutrient} & 475 & 25 & 500 \\
\hline \text{Doesn't contain nutrient} & 18 & 282 & 300 \\
\hline \text{Total} & 493 & 307 & 800 \\
\hline
\end{array}
\][/tex]

What is the probability that the result of the test is negative, given that the sample doesn't contain the nutrient?

A. 92%
B. 94%
C. 96%
D. 95%



Answer :

To solve this problem, we need to determine the probability that the result of the test is negative, given that the sample doesn't contain the nutrient.

We are given the following information in the table:

- Total number of samples that don't contain the nutrient: 300
- Number of these samples that tested negative: 282

The probability we are looking for is the probability that the test is negative given that the sample doesn't contain the nutrient, which can be calculated using the formula:

[tex]\[ P(\text{Negative} | \text{No Nutrient}) = \frac{\text{Number of negative tests for samples without nutrient}}{\text{Total number of samples without nutrient}} \][/tex]

Plugging in the given values:

[tex]\[ P(\text{Negative} | \text{No Nutrient}) = \frac{282}{300} \][/tex]

Next, we convert this probability to a percentage:

[tex]\[ \frac{282}{300} \approx 0.94 \][/tex]

Then, we multiply by 100 to get the percentage:

[tex]\[ 0.94 \times 100 = 94\% \][/tex]

Thus, the correct answer is:
[tex]\[ 94\% \][/tex]