Historians and biographers have collected evidence that suggests that President Andrew Jackson suffered from mercury poisoning. Researchers have measured the amount of mercury in samples of Jackson’s hair from 1815. The results of this experiment showed that Jackson had a mean mercury level of 6.0 ppm.

(a) Levels of mercury in hair samples from that time period followed a normal distribution with mean 6.9 and standard deviation 4.6. Find the probability that a randomly selected person from that time period would have a mercury level of 6.0 ppm or higher. Discuss whether this provides evidence that Jackson suffered from mercury poisoning during this time period.

(b) Today’s accepted normal mercury levels follow a normal distribution with approximate mean of 0.6 ppm and standard deviation of 0.3 ppm. By today’s standards, how likely is it that a randomly selected person from today would have a mercury level of 6.0 ppm or higher? Discuss whether we can conclude from this that Andrew Jackson suffered from mercury poisoning.