Question: It is known that the distribution of IQ scores is normal with population mean 100 and standard deviation 15. Studies reported in USA TODAY (April 21, 2011) found that children exposed to pesticides before birth had lower average IQs than children who were not exposed. In particular, exposure to lead caused a 2 to 3 point drop in average IQ. This small difference " ... can have an enormous impact, ..." according to a pediatrician at Children's Hospital Boston, causing a "...big jump in the number of kids with low intelligence and a dramatic loss in the number of super-smart ones."

Consider low intelligence to be 70 or below, and "super-smart" to be 130 and above. Investigate the impact of a 2-point drop in population average IQ. Assume the standard deviation remains the same. (Hint: Use a web calculator.)