Answer the question based on the data in the table.

\begin{tabular}{|c|c|c|c|c|}
\hline
\multirow{2}{*}{\begin{tabular}{c}
Hemoglobin \\
Level
\end{tabular}} & \multicolumn{4}{|c|}{ Person's Age } \\
\cline { 2 - 5 } & \begin{tabular}{c}
Less than \\
25 years
\end{tabular} & [tex]$25-35$[/tex] years & Above 35 years & Total \\
\hline
Less than 9 & 21 & 32 & 76 & 129 \\
\hline
Between 9 and 11 & 49 & 52 & 40 & 141 \\
\hline
Above 11 & 69 & 44 & 162 & 275 \\
\hline
Total & 139 & 128 & 278 & 545 \\
\hline
\end{tabular}

Select the correct answer.
What is the probability that a person who is older than 35 years has a hemoglobin level between 9 and 11?

A. 0.257
B. 0.284
C. 0.312
D. 0.356



Answer :

To find the probability that a person who is older than 35 years has a hemoglobin level between 9 and 11, we follow these steps:

1. Identify the total number of people who are older than 35 years:
According to the table, the numbers of people older than 35 years in each hemoglobin level category are:
- Less than 9: 76
- Between 9 and 11: 40
- Above 11: 162

Adding these values gives the total number of people older than 35 years:
[tex]\[ 76 + 40 + 162 = 278 \][/tex]

2. Identify the number of people older than 35 years with a hemoglobin level between 9 and 11:
The number of people older than 35 years with a hemoglobin level between 9 and 11 is given as 40.

3. Calculate the probability:
The probability is found by dividing the number of people older than 35 years with a hemoglobin level between 9 and 11 by the total number of people older than 35 years:
[tex]\[ \text{Probability} = \frac{\text{Number of people with hemoglobin level between 9 and 11}}{\text{Total number of people older than 35 years}} \][/tex]
Plugging in the numbers:
[tex]\[ \text{Probability} = \frac{40}{278} \approx 0.1439 \][/tex]

Thus, the probability that a person who is older than 35 years has a hemoglobin level between 9 and 11 is approximately [tex]\(0.1439\)[/tex].

Since [tex]\(0.1439\)[/tex] is not one of the provided answer choices (A, B, C, or D), there might be a mistake in the question's options or the table data provided. Otherwise, based on the given table data, the correct probability calculation is as described above.