 Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum            Session 3, Part A:
Organizing Data in a Stem and Leaf Plot

In This Part:
How Long Is a Minute? | Making a Stem and Leaf Plot | Ordering a Stem and Leaf Plot
Interpreting the Stem and Leaf Plot | Grouping by Fives | Ordering Low and High

The ordered stem and leaf plot from Problem A3 looks like this: A stem and leaf plot shows us potential patterns in the responses that may not be apparent in the original listing of the data. For example, we can see that a large number of data values are in the 50s and 60s. Ordering a stem and leaf plot offers another way to represent the answers to our question, "How well do people judge when a minute has elapsed?"  Problem A4 Based on the ordered stem and leaf plot:

 a. How many of the estimates are between 33 and 89 seconds (inclusive)? b. How many of the estimates are between 52 and 68 seconds (inclusive)? Problem A5 Since the goal is to estimate when a minute has elapsed, it makes sense to consider how close the estimates are to the correct response, which is 60 seconds.

 a. How many people's estimates were more than five seconds away from one minute? That is, how many of the responses were less than 55 seconds or greater than 65 seconds? b. How many estimates were within five seconds of one minute? c. How many estimates were more than 10 seconds away from one minute? d. How many estimates were within 10 seconds of one minute? Problem A6 a. Determine the mean of this data set. How does the mean compare to the correct response of 60 seconds? b. How many people's estimates were more than 5 seconds away from the mean? c. How many people's estimates were more than 10 seconds away from the mean? d. Why is it not useful to calculate the mode for this data set?  The mean can be found by adding all the data values and dividing by the total number of values in the set.   Close Tip The mean can be found by adding all the data values and dividing by the total number of values in the set. Asking and answering questions like the ones in Problems A5 and A6 can help us learn more about the variation present in a data set, they are important questions to consider as we interpret our data.   Session 3: Index | Notes | Solutions | Video