The amount of fish caught per week on a trawler is a function of the crew size assigned to operate the boat. Based on past data, the following production schedule was developed:

CREW SIZE (NUMBER AMOUNT OF FISH CAUGHT PER
OF WORKERS) WEEK (HUNDREDS OF LBS)
2 .................... 3 3.................. .. 6
4 ................... 11
5 ................... 19
6 ................... 24
7 ................... 28
8 ................... 31
9 ................... 33
10 .................... 34
11 .................... 34
12 .................... 33

a. Over what ranges of workers are there
(i) Increasing,
(ii) Constant,
(iii) Decreasing, and
(iv) Negative returns?
b. How large a crew should be used if the trawler owner is interested in maximizing the total amount of fish caught?
c. How large a crew should be used if the trawler owner is interested in maximizing the average amount of fish caught per person?