Texas Instruments TI-30X Teachers Guide - Page 22

Heart Rates - 1-Variable Statistics (Continued) 4. Check the statistics calculations. After students display Òx (Sigma x), explain that Òx is the sum of all the heart rates. Ask students: • How many heartbeats were there in one minute? • Is the average heart rate higher or lower than you expected? 5. Now we will see the effect of some exercise on heart rate. Tell students: If at any point during this portion of the activity you experience pain, weakness, or shortness of breath, stop immediately. 6. Have the students run in place for 2 minutes and then give them these instructions: a. Time your pulse for 1 minute. b. Record your heart rate as before. c. Enter the data into the calculator. d. Compare the average heart rate after running with the resting heart rate. 7. Now have the students do jumping jacks for 2 minutes. Instruct them to time their pulse for 1 minute again and record as before. Have them enter the data into the calculator again and calculate the average heart rate after jumping jacks. Compare to the other 2 averages. 8 How fit is the class? If the class (or individual) heart rate after jumping jacks is less than 90, then you are in great shape. If it is higher than 125, then you are in poor shape. 9. Instruct students to make a histogram of the 3 sets of data they collected. Ask students: • How are the histograms the same? • How are they different? • Is the data grouped the same or is it more spread out in one graph compared to another?  1. Press u. n Ï Sx Îx 22. n should equal the total number of student sampled. 2. Press " to Ï to see the average heart rate. n Ï Sx Îx 62. 3. Press " " " to Òx. Òx Òx 2 1370. Note: The numbers show the results of the example described above. Your students' results will vary depending on the size of group and the heart rate readings. © 1999 TEXAS INSTRUMENTS INCORPORATED TI-30X ÙS: A Guide for Teachers 18