Step 1 Probability of an event is ratio of total number of favourable outcomes for the event to total number of possible outcomes of the experiment. If there are two event A and B, the probability of event A when event B has already been occurred, is called conditional probability. The formula of conditional probability is P (A mid B)= (P (A ∩ B))/(P (B))the value P (A ∩ B) represents the probability when both the events A and B occurs together. Step 2 Lets A denotes the event that flight arrives on time and 8 represents the event that the flight departures on time, So the given probabilities are P (A)=0.92, P (D)=0.83 text and P (A ∩ D)=0.78. For the first part, apply the conditional probability formula to find the value of P (A mid D) and substitute the values. P (A mid D) (P (A ∩ D))/(P (D)) = (0.78)/(0.83) ~0.94 So the probability that the arrival is on time when the departure was on time will be ~imately 0.94. Step 3 For the next part, apply the conditional probability formula to find the value of P (D mid A) and substitute the values. NSP P (D mid A) (P (A ∩ D))/(P (A)) = (0.78)/(0.92) ~0.85 So the probability that the departure was on time when the arrival was on time will be ~imately 0.85.