Of the delegates at a convention, 60% attended the breakfast forum, 70% attended the dinner speech and 40% attended both events. If a randomly selected delegate is known to have attended the dinner speech, the probability that he also attended the breakfast forum is

Respuesta :

Answer:

The probability that he also attended the breakfast forum is is 0.5714 = 57.14%.

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

[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.

In this question:

Event A: Attended the dinner speech.

Event B: Attended the breakfast forum.

70% attended the dinner speech

This means that [tex]P(A) = 0.7[/tex]

40% attended both events.

This means that [tex]P(A \cap B) = 0.4[/tex]

The probability that he also attended the breakfast forum is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.4}{0.7} = 0.5714[/tex]

The probability that he also attended the breakfast forum is is 0.5714 = 57.14%.