Solve the below problem:
Q: A study by Bechtel et al., 2009, described in the Archives of Environmental & Occupational Health considered polycyclicaromatic hydrocarbons and immune system function in beef cattle. Some cattle were near major oil- and gas-producing areas of western Canada. The mean monthly exposure to PM1.0 particulate matter that is
(a) What is the probability of a monthly exposure greater than 9 µg/m3?
(b) What is the probability of a monthly exposure between 3 and 8 µg/m3?
(c) What is the monthly exposure level that is exceeded with probability 0.05?
(d) What value of mean monthly exposure is needed so that the probability of a monthly exposure more than 9 µg/m3 is 0.01?