The accompanying data came from a study of collusion in bidding within the construction industry ("Detection of Collusive Behavior," J. of Construction Engr. and Mgmnt, 2012: 1251-1258).
No. Bidders _________No. Contracts
2 ......................................... 7
3 ........................................ 20
4 ........................................ 26
5 ........................................ 16
6 ........................................ 11
7 ......................................... 9
8 ......................................... 6
9 ......................................... 8
10 ....................................... 3
11 ....................................... 2
a. What proportion of the contracts involved at most five bidders? At least five bidders?
b. What proportion of the contracts involved between five and 10 bidders, inclusive? Strictly between five and 10 bidders?
c. Construct a histogram and comment on interesting features.