Questions: Find the indicated probability. Express your answer as a simplified fraction unless otherwise noted.
The table below describes the smoking habits of a group of asthma sufferers.
Nonsmoker Light smoker Heavy smoker Total
------------------------------------------------------
Men 315 54 72 441
Women 308 86 93 487
Total 623 140 165 928
If one of the 928 subjects is randomly selected, find the probability that the person chosen is a woman given that the person is a light smoker. Round to nearest thousandth.
Transcript text: Find the indicated probability. Express your answer as a simplified fraction unless otherwise noted.
The table below describes the smoking habits of a group of asthma sufferers.
| | Nonsmoker | Light smoker | Heavy smoker | Total |
|--------|-----------|--------------|--------------|-------|
| Men | 315 | 54 | 72 | 441 |
| Women | 308 | 86 | 93 | 487 |
| Total | 623 | 140 | 165 | 928 |
If one of the 928 subjects is randomly selected, find the probability that the person chosen is a woman given that the person is a light smoker. Round to nearest thousandth.
Solution
Solution Steps
To find the probability that a randomly selected person is a woman given that the person is a light smoker, we use conditional probability. The formula for conditional probability is P(A|B) = P(A and B) / P(B). Here, A is the event that the person is a woman, and B is the event that the person is a light smoker. We need to find the number of women who are light smokers and divide it by the total number of light smokers.
Step 1: Identify Events
Let \( A \) be the event that the person chosen is a woman, and let \( B \) be the event that the person is a light smoker. We need to find \( P(A|B) \).
Step 2: Use Conditional Probability Formula
The formula for conditional probability is given by:
\[
P(A|B) = \frac{P(A \cap B)}{P(B)}
\]
Step 3: Calculate \( P(A \cap B) \) and \( P(B) \)
From the table, we have:
\( P(A \cap B) \) (the probability of being a woman and a light smoker) is represented by the number of women who are light smokers, which is \( 86 \).
\( P(B) \) (the total number of light smokers) is \( 140 \).
Step 4: Calculate the Probability
Now we can substitute the values into the formula: