Question

If there is a 70% chance of rain tomorrow and a 50% chance of wind and rain, what is the probability that it is windy, given that it is rainy? Round your answer to the nearest percent. A. 67% B. 71% C. 78% D. 33%

Answer 1

P(R) = 0.7

`P(R\cap W)=0.5`

`P(W)=(P(R\cap W))/(P(R))=(0.5)/(0.7)=0.71`
The correct choice of answer is B. 71%.

Answer 2

The chance of raining tomorrow (B) is 70% while the chance of having a windy (A) and rainy weather is 50%. The chance hat it is windy, given that it is rainy is obtained from the rule of probability: p(A/B) = p (A and B) / p (B)
substituting,
p(A/B) = 0.50/0.70 equal to 0.7143