Fuel Consumption and Cars
The battery manufacturer Varta sells a car battery with 800 coldcranking amps and advertises great performance even in bitingly cold weather. Varta claims that after sitting on a frozen Minnesota lake for 10 days at temperatures below 32°F, this battery will still have enough power to start a car. Suppose the actual probability of starting a car following this experiment is 0.75, and 15 randomly selected cars (equipped with this battery) are subjected to these grueling conditions.
a. Find the probability that fewer than 10 cars will start. Write a Solution Trail for this problem.
b. Find the probability that more than 12 cars will start.
c. Suppose 9 cars actually start. Is there any evidence to suggest that the probability of starting a car is different from 0.75? Justify your answer.