It the 1980s, it was generally believed that congenital abnormalities affected about 7% of a large nation's children. some people believe that the increase in the number of chemicals in the environment has led to an increase in the incidence of abnormalities. a recent study examined 433 randomly selected children and found that 48 of them showed signs of an abnormality. is this strong evidence that the risk has increased? (we consider a p-value of around 5% to represent reasonable evidence.) assume the independence assumption is met.