An very interesting activity is to have students measure the circumference of their wrists and the circumference of their necks. Make a scatter plot of these values. The students can quickly see a strong, positive, association between the two. Have them draw a "typical" line that gives the best fit to the relationship. Have teams of students pick two random data points that seem to be on this line and compute the slope and equation of the line using traditional algebra techniques (y = ax + b). Compare the equations and see how close they are.
Then use technology to find the actual regression line. See which students came the closest. Use their line and the actual regression to compute y-hat and the correlation coefficient along with r-squared. This helps them to see the meaning of the line with best fit and the best correlation coefficient.
Now they are able to gain an physical nderstanding of the slope in this problem. As wrist size increases by 1 cm, the neck size increases by "a" cm (where a is the slope of the line). Choose a few students at random and see how well the equation predicts their neck size. Try the prediction on a few people who were not part of the original sample (sucj as the visitors) and see how accurately the equation works for them. Have the students brainstorm as to reasons why the other people do or do not fit the predicted equation.
Acitivities that involve the students in active learning do the best job in helping them understand the concepts not the just the mechanics. It always impresses visitors to see students working excitedly on math. Involving the visitors insures their atttention to the lesson as well.
Good luck, Larry
Larry Peterson Bonneville High School Home 251 E Laker Way 4470 S 1650 W Ogden, Utah 84405 Roy, Utah 84067 801-476-5808 801-731-4267