Problem 21E

Education The responses of 1026 U.S. adults to a survey about the quality of public schools are shown in the Pareto chart. Find each probability. (Adapted from CBS News Poll)

(a) Randomly selecting a person from the sample who did not give the public schools an A

(b) Randomly selecting a person from the sample who gave the public schools a grade better than a D

(c) Randomly selecting a person from the sample who gave the public schools a D or an F

(d) Randomly selecting a person from the sample who gave the public schools an A or a B

How Would You Grade the Quality of Public Schools in the U.S.?

Answer

Step 1 of 4

(a)

The responses of 1026 U.S. adults to a survey about the quality of public schools are shown in the Pareto chart.

We are asked to find the probability of randomly selecting a person from the sample who did not give the public schools an

Empirical (or statistical) probability is based on observations obtained from probability experiments. The empirical probability of an event E is the relative frequency of event E.

Hence using the definition and from the Pareto chart the total number of responses is

The number of person from the sample who did not give the public schools an is,

Hence the probability of randomly selecting a person from the sample who did not give the public schools an is