1. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Bell Ringer
1) In the data set below, what is the mean absolute deviation? If the answer is a decimal, round it to the nearest tenth. (Alg. 1 KK.6)
𝟏𝟒.𝟑
2) In the data set below, what is the variance? If the answer is a decimal, round it to the nearest tenth. (Alg. 1 KK.7)
𝟗𝟕𝟔.𝟑

2. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Objective: To identify sampling methods and to recognize bias in samples and surveys.
Getting Ready!
One day, you catch 100 fish at random from a lake. You tag the fish and then release them back into the lake. The next day you again catch 100 fish at random, as shown on the map. The red dots indicate the fish that have your tags. What can you conclude? Justify your conclusion.
What is the minimum number of fish in the pond? How do you know?
Of the 100 fish caught on the second day, only 3 are the same fish caught on the previous day. There must be at least 𝟏𝟎𝟎 – 𝟑 = 𝟗𝟕 more fish in the lake in addition to the 100 caught on the fist day. So there must be at least 197 fish in the lake.

3. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Population
is all the members of a set

4. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Sample
is part of a population

5. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Convenience sample

6. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Self-selected sample

7. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Systematic sample
Order the population in some way, and then select from it at regular intervals

8. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Random sample
all members of the population are equally likely to be chosen.

9. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Bias
A systematic error introduced by the sampling method.
Bias is the tendency of a statistic to overestimate or underestimate a parameter (numerical characteristic of a population).

10. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Example 1
Analyzing sampling method

11. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Example 1
Analyzing sampling method

12. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Example 1
Analyzing sampling method

13. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Analyzing sampling method

14. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey

15. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Observation Study
You measure or observe members of a sample in such a way that they are not affected by the study.

16. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Controlled Experiment
You divide the sample into two groups. You impose a treatment on one group but not the other “control” group. Then you compare the effect on the treated group to the control group.

17. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Survey
You ask every member of the sample a set of questions.

18. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Example 2
Analyzing study method

19. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Example 2
Analyzing study method

20. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Example 2
Analyzing study method

21. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Analyzing sample method

22. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Example 3
Designing a survey

23. International Studies Charter School.
Mrs. Rivas
International Studies Charter School.
Algebra 2 Section 11-8
Sample and Survey
Designing a survey

24. Mrs. Rivas Pg. 728 to 724 # 1 to 5 and 6-24 Even and 29, 30, 36, 38
IXL-Geometry X1, X2 and X3 and Alg 1 KK6 and KK7