Determine whether the conclusion is valid. Justify your answer.

1. To decide what main dish to serve at her wedding, Jeanne

asks 50 of her friends and family whether they prefer fish or

chicken. Of these, 60% choose chicken. She concludes that

she will serve chicken at the wedding.

2. To determine the percentage of vacation time employees

take, a company randomly selects 50 employee records

from the company's database. What type of sample is used

in this experiment?

Course 2, Lesson 10-3

Course 2, Lesson 10-3

ANSWERS

1. The conclusion is valid. Because the

people she surveyed will be attending her

wedding, they are representative of the

entire population of guests.

2. Simple random sampling

HOW do you know which type of graph to use

when displaying data?

Statistics and Probability

Course 2, Lesson 10-3

Course 2, Lesson 10-3 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

Statistics and Probability

• Extension of 7.SP.1Understand that statistics can be used to gain information about a population by examining a sample of the population; generalizations about a population from a sample are valid only if the sample is representative of that population. Understand that random sampling tends to produce representative samples and support valid inferences.

Mathematical Practices1 Make sense of problems and persevere in solving them.3 Construct viable arguments and critique the reasoning of others.4 Model with mathematics.

•To identify a misleading graph•To explain how statistics might be misleading

Course 2, Lesson 10-3

Statistics and Probability

How did what you learned today help you answer the

HOW do you know which type of graph to use

when displaying data?

Course 2, Lesson 10-3

GeometryStatistics and Probability

How did what you learned today help you answer the

HOW do you know which type of graph to use

when displaying data?

Course 2, Lesson 10-3

GeometryStatistics and Probability

Sample answers:• When the graph of real-life data might be misleading • When understanding how statistics can be used to

influence conclusions

List some of the things youshould look for when determining

whether a graph or statisticalmeasure is misleading.

Course 2, Lesson 10-3

Ratios and Proportional Relationships

FunctionsStatistics and Probability