1. Could we use a random sample to discover whether or not peoples’ education level impacts their likelihood to vote in a presidential election?

2. In this lesson you will learn how to make inferences about a population with an unknown characteristic by analyzing random samples.

3. Let’s Review Representative sample Valid inference Random sampling method

4. A Common Mistake Blue is the preferred color. Some students make an inference or generalization even if the data doesn’t show a significant pattern.

5. Core Lesson ? Trout Walleye Whitefish ?? ? Unknown characteristic

6. ?? ? Random sample: 300 fish 45 Walleye 130 Whitefish 125 Trout Inferences about population

7. Core Lesson More/less than Twice as many as Tends to increase/decrease Making inferences

8. Core Lesson 45 Walleye 130 Whitefish 125 Trout Random Sample There are more trout and whitefish than walleye in the lake There are about 1/3 as many walleye as trout or whitefish Whitefish is the most common fish Inferences

9. In this lesson you have learned how to make inferences about a population with an unknown characteristic by analyzing random samples.

10. Guided Practice What inferences can be made from the graph? Data: Survey of a random sample of Americans

11. Extension Activities Which is the most valid inference?  Black is the least preferred color.  More students prefer blue than prefer black and green combined.  Blue and green are the preferred colors.  Pink is preferred to black. BlackYellowGreenPinkBlueTOTAL 7410521579227700

12. Extension Activities TOTAL Create a survey question and five possible responses. Collect data from a sample of your class in a table like the one below. Make two inferences about your entire grade by analyzing the data from your sample.

13. Extension Activities Explain why Kyle’s inference may be invalid. Kyle: People with graduate degrees vote more often than people with only college degrees.

14. Quick Quiz To predict middle school students’ ice cream preferences, a random sample of 1,300 students was surveyed about their preferences between ice cream flavors. ChocolateVanillaMint Chocolate Chip StrawberryCookie Dough TOTAL 1942103501903561300 1) Make two inferences about the population.

15. Quick Quiz 2) Which is the most valid inference from this sample data? a)Strawberry is the least preferred flavor. b) More students prefer cookie dough ice cream than prefer chocolate and vanilla combined. c) Cookie dough and mint chocolate chip are the preferred ice cream flavors. d) Chocolate ice cream is preferred to strawberry