Mercury in Freshwater Fish
Some experts believe that 20% of all freshwater fish in the United States have such high levels of mercury that they are dangerous to eat.
Suppose a fish market has 250 fish tested, and 60 of them have dangerous levels of mercury. Test the hypothesis that this sample is not from a population with 20% dangerous fish.
Use a significance level of 0.05. Comment on your conclusion: Are you saying that the percentage of dangerous fish is definitely 20%? Explain.