Answer: The probability that a randomly selected tire will have a tread-life of less than 65,000 miles is 0.7872 .
Step-by-step explanation:
The cumulative distribution function for exponential distribution is :-
, where
is the mean of the distribution.
As per given , we have
Average tread-life of a certain brand of tire :
Now , the probability that a randomly selected tire will have a tread-life of less than 65,000 miles will be :
Hence , the probability that a randomly selected tire will have a tread-life of less than 65,000 miles is 0.7872 .