Upward Bound Prejunior Practical Mathematics Linear equation via GPS walk

The class went outside to the frontage entrance road. Using an eTrex Garmin GPS - one of the most basic unit on the market, the class walked off 120 meters of road. Every 30 meters sidewalk chalk was used to mark the road. Then the class went back to the start and measured their time in seconds to pass each 30 meter chalk mark. Back in class this data was recorded in a table and graphed. The class was then instructed in finding a best fit line, rise, run, slope, point-slope form, and slope-intercept forms of linear equations using the data. A quiz that includes this work is available on line. The data below is available in an OpenOffice.org Calc spreadsheet.

Walk Run
x: time/sec y1:dist/m y2/dist/m
0 0 0
16 60
23 90
30 30 120
55 60
80 90
104 120
slope m/s 1.16 3.99
intercept m -2.44 -1.27