Question 6 options:

The caller times at a customer service center has an exponential distribution with an average of 22 seconds. Find the probability that a randomly selected call time will be less than 30 seconds? (Round to 4 decimal places.) Answer:

Question 7 options:

The life of an electric component has an exponential distribution with a mean of 7.2 years. What is the probability that a randomly selected one such component has a life less than 4 years? Answer: (round to 4 decimal places)

question 8

Suppose that the longevity of a light bulb is exponential with a mean lifetime of 7.6 years. Find the probability that a light bulb lasts less than three years.

question 9

The average lifetime of a certain new cell phone is 3.4 years. The manufacturer will replace any cell phone failing within three years of the date of purchase. The lifetime of these cell phones is known to follow an exponential distribution. 68% of these phone last how long (in years)?

Question 10 options:

Miles per gallon of a vehicle is a random variable with a uniform distribution from 22 to 39. The probability that a random vehicle gets between 26 and 31 miles per gallon is: Answer: (Round to four decimal places)