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 .
Answer: a). 5
Explanation:
5 > 4
3:5 my answer has to be 20 characters so im just typing the rest of this to answer your question.
87.4 people per square mile