In this activity, you’ll get two chances to guess at how long 30 seconds is, then look for an association between the two guesses of all students.
- Work with a partner. Follow the instructions listed here to gather your data.
- One of you will hold a stopwatch where the other person cannot see it.
- The person holding the stopwatch says “go” and starts the timer.
- The other person says “stop” when they think 30 seconds have passed.
- The person holding the stopwatch will stop the timer, then report and record the time to the nearest second.
- The person holding the stopwatch will give a second chance, repeating the experiment.
- After both times are recorded, switch roles.
Record the group data in this table. When you finish, a group member should give the data to the teacher.
name time 1 time 2
Look at your data. Comparing Time 1 to Time 2, do you think there is a positive association, a negative association, or no association? Discuss your thinking with your group.
What are some ways you could organize and represent the entire class's data?
Make a scatter plot of the entire class’s data and look for patterns. Identify any outliers and the type of any association you observe.
Draw two lines on your scatter plot: a vertical line and a horizontal line, each representing 30 seconds for one trial. Use the table for the class’s data to complete this two-way table.
Time 2 < 30 sec Time 2 = 30 sec Time 2 > 30 sec total Time 1 < 30 sec Time 1 = 30 sec Time 1 > 30 sec total
Use the two-way table to decide whether there is an association between Time 1 and Time 2. Explain how you know.