Wednesday 03 February 2010 I ran from Dolihner up towards Pit Stop, circled around past PICS, down to Kaselehlie and Elenieng, out to the U border, back into town through the public market, up to Spanish wall, up main street and back into Dolihner. Using a global positioning satellite receiver (GPS) and a chronometer I determined both my distance in kilometers and my time in minutes. In the world of running, a key metric is one's pace. Pace is the number of minutes per kilometer. Pace is not speed. Pace is the inverse of speed. A small pace is fast, a large pace is slow. For pace x is the distance and y is the time.
Remember that best fit line, least squares, linear regression, and linear trend line all mean the same thing.
______________ Determine the slope of the linear trend line for the data.
______________ Determine the y-intercept of the linear trend line for the data.
______________ As I reached my turn-around at the bridge on the border between U and Nett my GPS said I was 7.45 kilometers into my run. I did not check my chronometer. Use the slope and intercept determined above to calculate the time in minutes at which I reached the U border.
______________ At an hour I usually try to rehydrate by picking up a bottle of water or a packet of juice. Using the above slope and intercept, determine my distance in kilometers at the one hour mark (60 minutes).
______________ On Saturday 08 September the Liberation day half-marathon covered 19.34 km. Based on the slope and intercept above, predict my time to complete 19.34 km.
______________ On Saturday 08 September I ran 19.34 km in 133 minutes and ten seconds. Was I faster or slower than the predicted time?
