At LaGuardia Airport for a certain nightly flight, the probability that it will rain is 0.19 and the probability that the flight will be delayed is 0.17 . The probability that it will rain and the flight will be delayed is 0.05 . What is the probability that it is not raining if the flight leaves on time? Round your answer to the nearest thousandth.Answer:
Q. At LaGuardia Airport for a certain nightly flight, the probability that it will rain is 0.19 and the probability that the flight will be delayed is 0.17 . The probability that it will rain and the flight will be delayed is 0.05 . What is the probability that it is not raining if the flight leaves on time? Round your answer to the nearest thousandth.Answer:
Events Denotation: Let's denote the events as follows:R: It will rain.D: The flight will be delayed.We are given the following probabilities:P(R)=0.19P(D)=0.17P(R and D)=0.05We want to find the probability that it is not raining given that the flight leaves on time. This can be expressed as P(Not R∣Not D), which is the conditional probability of it not raining given that the flight is not delayed.
Find Probability Not Delayed: First, we need to find the probability of the flight not being delayed, which is P(Not D). This is the complement of the flight being delayed, so we calculate it as:P(Not D)=1−P(D)P(Not D)=1−0.17P(Not D)=0.83
Find Probability Not Rain and Not Delayed: Next, we need to find the probability of it not raining and the flight not being delayed, which is P(Not R and Not D). This can be found by taking the complement of the probability of either raining or the flight being delayed. Using the Addition Rule of Probability, we have:P(R or D)=P(R)+P(D)−P(R and D)P(R or D)=0.19+0.17−0.05P(R or D)=0.31Now, we find the complement of P(R or D) to get P(Not R and Not D):P(Not R and Not D)=1−P(R or D)P(Not R and Not D)=1−0.31P(Not R and Not D)=0.69
Calculate Conditional Probability: Now we can use the definition of conditional probability to find P(Not R∣Not D). The formula for conditional probability is:P(Not R∣Not D)=P(Not D)P(Not R and Not D)Substituting the values we have found:P(Not R∣Not D)=0.830.69P(Not R∣Not D)≈0.8313
Final Probability Calculation: Finally, we round the answer to the nearest thousandth as requested: P(Not R∣Not D)≈0.831
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