). A company periodically tests its product for tread wear under simulated conditions. Thirty random samples, each containing 5 items, were taken in a control chart application and it was found that the grand average is

An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0