Rick wing, salesperson for wave soldering systems, inc. (wssi), has provided you with a proposal for improving the temperature control on your present machine. the machine uses a hot-air knife to cleanly remove excess solder from printed circuitboards; this is a great concept, but the hot-air temperature con- trol lacks reliability. according to wing, engineers at wssi have improved the reliability of the critical temperature controls. the new system still has the four sensitive integrated circuits control- ling the temperature, but the new machine has a backup for each. the four integrated circuits have reliabilities of .90, .92, .94, and .96. the four backup circuits all have a reliability of .90. a) what is the reliability of the new temperature controller? b) if you pay a premium, wing says he can improve all four of the backup units to 0.91. the overall reliability of the new temperature controller with the upgraded backup unit=%(rounded to two decimal places)