Question

At a car rental agency, 0.39 of the cars are returned on time. A sample of 12 car rentals is studied. What is the probability that more than 3 of them are returned on time?

Answer 1

Probabilty of more than 3 =0.8474

Explanation:

Probabilty of returned on time P= 0.39

Probabilty of not on time q=1-0.39= 0.61

Sample = 12 cars

Selected items = 3 cars

Probabilty of3 returned on time

= 12C3 * (0.39)^3 * (0.61)^9

= 220*(0.059319)*(0.011694146)

= 0.1526

Note**** C represents combination

So probability of more than 3 means greater than 3 = from 4 above

Probability of more than 3 = 1-probability of three

Probabilty of more than 3 = 1-0.1526

Probabilty of more than 3 =0.8474