Answer

High dose risk to rats = 5/200 = 1/40. Current low dose in humans is 2/1000, or 1/500, of the rat dose. The risk to humans is thus (1/40)*(1/500) = 1/20,000 or 10 fatalities in the given population. Reducing the human dose to 1 mg would lower the risk to (1/40)*(1/1,000) = 1/40,000, or 5 fatalities in the population. The value of reducing the dose is thus 5 lives saved times $6M or $30M.