+52 High concentrations of carbon monoxide CO can cause coma and possible death. The time required for a person to reach a COHb level capable of causing a coma can be approximated by the quadratic model T=.0002x^2-.316x127.9 where T is the exposure time in hours necessary to reach this level and
500l ≤ x ≤ 800 is the amount of carbon monoxide present in the air in parts per million (ppm).
a) What is the exposure time when x=800?
b) Estimate the concentration of CO necessary to produce a coma in 9 hr.
