You're going to investigate a statistical question of your choice one that requires data to answer. Then you'll gather, analyze, and display data from two different groups of subjects. Each of the two data sets should include a minimum of 10 data values. When you've finished your investigation, you'll prepare a brief report or presentation on your results.

After you gather your data, use these questions to help you analyze and display the data from your investigation.

The Statistical Question 1. State the statistical question you are investigating.

Collecting Data 2. Explain the collection method you used to gather your data.

3. What potential sources of bias were involved in your data collection method? Explain how you tried to deal with those.

4. Do your data represent a sample or the entire population? If they represent a sample, explain how you selected the sample to try to minimize bias.

5. Use one or more tables to list the data values in each of your two data sets.

6. Experimental error is a problem in all statistical and scientific studies. There are two main types of experimental error. Systematic error is something that consistently affects your results in a particular way. By being careful to avoid bias, you've gone a long way toward reducing systematic error in your study. Random error happens by chance: Your pen leaked, so you recorded some results incorrectly. Or your random sample happened to include a lot of people with strong opinions. You can't avoid random error. You can minimize it, however, by making sure that any particular result doesn't impact your overall results too much. Identify at least one way you could minimize the effects of random error on your study.

Summary Statistics: Measures of Center and Spread 7. Use a graphing calculator to find the mean, median, and standard deviation for each of your data sets. If necessary, round your answers to the nearest hundredth.

Data set	Mean	Median	Standard deviation
A
B

Displaying the Data8. Find the five-number summary for each of your data sets.

Data set	Minimum	First quartile	Median	Third quartile	Maximum
A
B

9. Create a box plot for each of your data sets. Label each box plot with its five-number summary. Use the same scale for both box plots so that you can compare them.

10. Calculate the IQR (interquartile range) for both of your data sets.

a. The IQR (interquartile range) for the first data set is _________.

b. The IQR (interquartile range) for the second data set is _________.

11. Identify any outliers in your data sets. Explain how you used the outlier formula to determine whether there were outliers.

Data set	Outliers above third quartile	Outliers below first quartile
A
B

12. Prepare a brief report or presentation on your results. Include in your report:

1. The question you investigated (1 point)
2. An explanation of how you gathered your data (2 points) and how you avoided introducing bias (2 points)
3. An analysis of the differences between your two data sets (2 points), including a comparison of your box plots (2 points)
4. A summary of what you learned, including a description of the differences and similarities between the measures of center and spread (2 points). Also explain why you chose each measure of center and spread (2 points).