In: Statistics and Probability
According to an airline, flights on a certain route are on time 8080% of the time. Suppose 1515 flights are randomly selected and the number of on-time flights is recorded. (a) Explain why this is a binomial experiment. (b) Find and interpret the probability that exactly 99 flights are on time. (c) Find and interpret the probability that fewer than 99 flights are on time. (d) Find and interpret the probability that at least 99 flights are on time. (e) Find and interpret the probability that between 77 and 99 flights, inclusive, are on time. (a) Identify the statements that explain why this is a binomial experiment. Select all that apply. A. The experiment is performed until a desired number of successes is reached. B. The trials are independent. C. The probability of success is the same for each trial of the experiment. D. The experiment is performed a fixed number of times. E. Each trial depends on the previous trial. F. There are two mutually exclusive outcomes, success or failure. G. There are three mutually exclusive possibly outcomes, arriving on-time, arriving early, and arriving late. (b) The probability that exactly 99 flights are on time is nothing. (Round to four decimal places as needed.) Interpret the probability. In 100 trials of this experiment, it is expected about nothing to result in exactly 99 flights being on time. (Round to the nearest whole number as needed.) (c) The probability that fewer than 99 flights are on time is nothing. (Round to four decimal places as needed.) Interpret the probability. In 100 trials of this experiment, it is expected about nothing to result in fewer than 99 flights being on time. (Round to the nearest whole number as needed.) (d) The probability that at least 99 flights are on time is nothing. (Round to four decimal places as needed.) Interpret the probability. In 100 trials of this experiment, it is expected about nothing to result in at least 99 flights being on time. (Round to the nearest whole number as needed.) (e) The probability that between 77 and 99 flights, inclusive, are on time is nothing. (Round to four decimal places as needed.) Interpret the probability. In 100 trials of this experiment, it is expected about nothing to result in between 77 and 99 flights, inclusive, being on time. (Round to the nearest whole number as needed.)
Solution:-
(a)
B) The trials are independent.
C) The probability of success is the same for each trial of the experiment.
D) The experiment is performed a fixed number of times.
F) There are two mutually exclusive outcomes, success or failure.
(b) The probability that exactly 9 flights are on time is 0.043.
x = 9, n = 15
By applying binomial distribution
P(x,n) = nCx*px*(1-p)(n-x)
P(x = 9) = 0.043
In 100 trials of this experiment, it is expected about 4 to result in exactly 9 flights being on time.
(c) The probability that fewer than 9 flights are on time.
x = 9, n = 15
By applying binomial distribution
P(x,n) = nCx*px*(1-p)(n-x)
P(x < 9) = 0.0181
In 100 trials of this experiment, it is expected about 2 to result in fewer than 9 flights being on time.
(d) The probability that at least 9 flights are on time is 0.9819.
x = 9, n = 15
By applying binomial distribution
P(x,n) = nCx*px*(1-p)(n-x)
P(x > 9) = 0.9819
In 100 trials of this experiment, it is expected about 98 to result in at least 9 flights being on time.
(e) The probability that between 7 and 9 flights, inclusive, are on time is 0.0569
x1 = 7, x2 = 9
By applying binomial distribution
P(x,n) = nCx*px*(1-p)(n-x)
P(7 < x < 9) = P(x > 7) - P(x > 9)
P(7 < x < 9) = 0.9958 - 0.9389
P(7 < x < 9) = 0.0569
In 100 trials of this experiment, it is expected about 6 to result in between 7 and 9 flights, inclusive, being on time.