Discover a world of knowledge at Westonci.ca, where experts and enthusiasts come together to answer your questions. Ask your questions and receive detailed answers from professionals with extensive experience in various fields. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform.

Select the correct answer:

\begin{tabular}{|c|c|c|c|c|}
\hline
Weight & 1000 to 1500 cal & 1500 to 2000 cal & 2000 to 2500 cal & Total \\
\hline
120 lb & 90 & 80 & 10 & 180 \\
\hline
145 lb & 35 & 143 & 25 & 203 \\
\hline
165 lb & 15 & 27 & 75 & 117 \\
\hline
Total & 140 & 250 & 110 & 500 \\
\hline
\end{tabular}

Based on the data in the two-way table, what is the probability that a person weighs 120 pounds, given that he or she consumes 2000 to 2500 calories per day?

A. 0.09
B. 0.12
C. 0.22
D. 0.35

Sagot :

To find the probability that a person weighs 120 pounds given that they consume 2000 to 2500 calories per day, we can use the concept of conditional probability. The formula for conditional probability is:

[tex]\[ P(A|B) = \frac{P(A \cap B)}{P(B)} \][/tex]

In this problem:
- [tex]\( A \)[/tex] is the event that a person weighs 120 pounds.
- [tex]\( B \)[/tex] is the event that a person consumes 2000 to 2500 calories per day.

From the given data:
- The total number of people consuming 2000 to 2500 calories per day is 110.
- The number of people who weigh 120 pounds and consume 2000 to 2500 calories per day is 10.

So, the probability that a person weighs 120 pounds given that they consume 2000 to 2500 calories per day is calculated as:

[tex]\[ P(\text{120 lb} | \text{2000 to 2500 cal}) = \frac{\text{Number of people who weigh 120 lb and consume 2000 to 2500 cal}}{\text{Total number of people who consume 2000 to 2500 cal}} \][/tex]

[tex]\[ P(\text{120 lb} | \text{2000 to 2500 cal}) = \frac{10}{110} \][/tex]

Upon simplifying this fraction, we get approximately [tex]\( 0.0909 \)[/tex]. Therefore, the correct answer to the question is:

A. 0.09