Respuesta :
Using probability concepts, it is found that:
1. P(B|A) = 0.4.
2. [tex]P(A \cap B) = 0.1575[/tex]
3. B. A is true given that B is true
4. Since [tex]P(A \cap B) = P(A)P(B)[/tex], they are dependent.
5. Since [tex]P(A \cap B) \neq P(A)P(B)[/tex], they are independent.
Conditional Probability
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
- P(B|A) is the probability of event B happening, given that A happened.
- [tex]P(A \cap B)[/tex] is the probability of both A and B happening.
- P(A) is the probability of A happening.
Item 1:
Applying conditional probability:
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.14}{0.35} = 0.4[/tex]
Hence, P(B|A) = 0.4.
Item 2:
[tex]P(A|B) = \frac{P(A \cap B)}{P(B)}[/tex]
[tex]0.35 = \frac{P(A \cap B)}{0.45}[/tex]
[tex]P(A \cap B) = 0.35(0.45)[/tex]
[tex]P(A \cap B) = 0.1575[/tex]
Item 3:
A is true given that B is true, hence, option B.
Item 4:
Two events, A and B, are dependent if:
[tex]P(A \cap B) = P(A)P(B)[/tex]
In this problem:
[tex]P(A \cap B) = \frac{3}{25}[/tex]
[tex]P(A)P(B) = \frac{3}{10} \times \frac{2}{5} = \frac{6}{50} = \frac{3}{25}[/tex]
Since [tex]P(A \cap B) = P(A)P(B)[/tex], they are dependent.
Item 5:
[tex]P(A|B) = \frac{P(A \cap B)}{P(B)}[/tex]
[tex]P(A \cap B) = P(B)P(A|B)[/tex]
[tex]P(A \cap B) = \frac{1}{4} \times \frac{21}{100}[/tex]
[tex]P(A \cap B) = \frac{21}{400}[/tex]
[tex]P(A)P(B) = \frac{7}{20} \times \frac{1}{4} = \frac{7}{80}[/tex]
Since [tex]P(A \cap B) \neq P(A)P(B)[/tex], they are independent.
To learn more about probability concepts, you can take a look at https://brainly.com/question/14398287