Math Word Problems Demystified - A Self Teaching Guide

IMPLEMENTATION:P(spade)¼

13

52

¼

1

4

.

EVALUATION: Use the sample space to verify your answer.

The examples shown previously are examples of what is calledclassical
probability. The next examples are from another area of probability called
empirical probability. Empirical probability uses frequency distributions.
Suppose that a bag of mixed candy contained 10 caramels, 8 peppermints,
4 chocolates, and 3 coconut creams. The sample space can be represented
using a frequency distribution as shown.

Candy Frequency

Caramels 10

Peppermints 8

Chocolates 4

Coconut creams 3

25

This distribution can be used to solve probability problems.

EXAMPLE:Suppose a person selects a piece of candy from the bag; find the
probability that it is a peppermint.

SOLUTION:

GOAL: You are being asked to find the probability that the piece of candy is
a peppermint.

STRATEGY: There are 8 peppermints and a total of 25 pieces of candy, so
the probability formula can be used.

IMPLEMENTATION:P(peppermint)¼

8

25

.

EVALUATION: The answer can be verified by looking at the frequency
distribution.

LESSON 22 Word Problems in Probability 271