UCSB PSTAT 109 Statistics for Economics Question-Quiz 2

Problem 1

 Find C1 ∪ C2 and C1 ∩ C2 if

(a) C1 = {0, 1, 2}, C2 = {2, 3, 4};

(b) C1 = {x : 0 < x < 2}, C2 = {x : 1 ≤ x < 3}.

Problem 2

Suppose our sample space is {(x, y) : x2 + y 2 ≤ 1}. What is the complement

of the set/event A = {(x, y) : x2 + y 2 = 1}?

Problem 3

 To join a certain club, a person must be either an economist, or a statistician,

or both. Of the total members in this club, 76% are economists, and 64% are statisticians.

What percentage of persons in the club are both an economist and a statistician?

Problem 4

 After a hard-fought football game, it was reported that, of the 11 starting

players, 8 hurt a hip, 6 hurt an arm, 5 hurt a knee, 3 hurt both a hip and an arm, 2 hurt

both a hip and a knee, 1 hurt both an arm and a knee, and no one hurt all three. Comment

on the accuracy of the report.