Suppose that the concentrations of mercury in individual fish in Lake Questionable follows an approximate normal distribution with a mean of 0.25 ppm and a standard deviation of 0.08 ppm.

ROUND ALL ANSWERS TO 3 DECIMAL PLACES.

Fish are safe to eat if the mercury level is below 0.30 ppm. What proportion of fish are safe to eat?

(a) What is the probability that a fish will have a mercury concentration greater than 0.19 ppm? = _____

(b) Fish from this lake are considered safe to consume so long as the mercury concentration does not exceed the 65 th percentile. What is maximum mercury concentration allowed for a fish to be consumed? = ____

(c) Due to growing demands for fish in this region, a small corporation has begun to overfish the lake. If a group of 20 fish are sampled, what proportion of this sample will have a mercury concentration less than 0.27 ppm. = _____