Refer to the U.S. Army Corps of Engineers data on contaminated fish in the Tennessee River, presented in Example. Recall that one of the variables measured for each captured fish is weight (in grams). The weights in the data set (saved in the DDT file) can be shown to be approximately normally distributed with a mean of 1,050 grams and a standard deviation of 375 grams. An observation is randomly selected from the data and the fish weight is observed.

a. Find the probability that the weight will fall between 1,000 and 1,400 grams.

b. Find the probability that the weight will fall between 800 and 1,000 grams.

c. Find the probability that the weight will be less than 1,750 grams.

d. Find the probability that the weight will exceed 500 grams. .9292

e. Ninety-five percent of the captured fish have a weight below what value? 1,666.875

f. Another variable saved in the DDT file is the amount of DDT (in parts per million) detected in each fish captured. Determine whether the DDT level is approximately normal.