Answer Happy

SHORT ANSWER. Show all necessary work. 11. Suppose that the lengths of incoming calls to a customer service center of a small credit union are uniformly distributed between 2 and 24 minutes. a. What is the probability that a randomly selected call lasts more than 15 minutes (if necessary, round to four decimal positions)? (10 points) b. What is the expected length of a call to this call center? (5 points) 12. A company's manufacturing process uses 500 gallons of water at a time. A "scrubbing" machine then removes most of a chemical pollutant before pumping the water into a nearby lake. To meet federal regulations the treated water must not contain more than 60 parts per million (ppm) of the chemical. Because a fine is charged if regulations are not met, the The company sets the machine to attain an average of 56 ppm in the treated water. machine's output can be described by a normal model with standard deviation 2.4 ppm. What percent of the batches of water discharged meet (t.e., less than or equal to) the 60 ppm standard (if necessary, round to four decimal positions)? (15 points) Page 3 of 4