At a fish farm, at the beginning of the season, the farmer releases a number of fry, which have a mark of 1000. In the fish harvest season, when 120 fish were randomly tested, they had an average weight of 1.6 kg, standard deviation was 0.21 kg, of which 15 were marked. With 95% confidence. a. Estimate the average weight of the total fish in the farm.
b. Estimate the range for the percentage of marked fish in the farm.
c. From sentence b, infer the number of fish in the range?
d. Assume the selling price of fish is VND 27,000/kg, and from the above sentences, calculate the farm's revenue from selling all the fish.
Please help me solve this !!!