Create a scatter plot on paper - it's best to do this on graph paper - using the data relating year and world record time on the 100 meter dash. Let the horizontal axis represent years, t, where t is the number of years after 1900. The vertical axis represents R, the time in seconds of the record 100 meter dash. Use a straight edge to draw the line you think is the best linear model for this data. Write the equation of that line here.