Respuesta :
Answer:
a) 0.3630 = 36.30% probability that the meteorologist predicts that it rains on a given summer day.
b) 0.5989 = 59.89% probability that it actually rains on the day of the wedding
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.
A. What is the probability that the meteorologist predicts that it rains on a given summer day?
80% of 25/92(prediction of rain, and rained).
20% of 67/92(prediction of rain, did not rain). So
[tex]P = \frac{0.8*25}{92} + \frac{0.2*67}{92} = 0.3630[/tex]
0.3630 = 36.30% probability that the meteorologist predicts that it rains on a given summer day.
B. Given that the meteorologist predicted rain, what is the probability that it actually rains on the day of the wedding?
Conditional Probability, in which:
Event A: prediction of rain
Event B: rain
0.3630 = 36.30% probability that the meteorologist predicts that it rains on a given summer day, which means that [tex]P(A) = 0.3630[/tex]
Rain and prediction of rain:
80% of 25/92. So
[tex]P(A \cap B) = \frac{0.8*25}{92} = 0.2174[/tex]
The desired probability is:
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.2174}{0.3630} = 0.5989[/tex]
0.5989 = 59.89% probability that it actually rains on the day of the wedding
