Business Statistics

Chapter 5 | Probability 163

The union of two sets X and Y is denoted by X È Y, which is a set containing all the elements that are

either members of X or Y or both. An element is the member of X È Y if it is a member of either X or

Y or is a member of both. For example,

X = {1, 2, 3, 4} and Y

= {5, 6, 7, 8}

X È Y = {1, 2, 3, 4, 5, 6, 7, 8}

The union of two sets X and Y, (X È Y) is exhibited graphically in Figure 5.2.

Intersection is denoted by the symbol . If there are two sets X and Y, the intersection of these

two sets is denoted by X  Y. The intersection of two sets X and Y, that is, X  Y is the set containing

all the elements that ...