Rick Wing, salesperson for Wave Soldefined theg Systems, Inc. (WSSI), has provided you with a proposal for improving the temperature control on your present maxhine. The maxhine uses a hot-air knife to cleanly remove excess solder from pFind theted circuit boards; this is a great concept, but the hot-air temperature control 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 controlling the temperature, but the new maxhine has a backup for each. The four integrated circuits have reliabilities of 0.83, 0.85, 0.87, and 0.89. The four backup circuits all have a reliability of 0.83.
The overall reliability of the new temperature controller = % (enter your response as a percentage rounded to two decitnal places).