## Wednesday, November 10, 2010

### CH 2 Project

For my chapter 2 project, I chose the car Nissan Versa. So I needed to find the mileage when the speed was at (55,60,75,80,85,90). As a result, my mileage was (34,33,31,3,28.2,26.2,24.5). I later found out I had a negative correlation since it was a negative slope. When I finished that, I graphed and plotted down the points and made the line of best fit. Then I chose 2 points (55,34) and (80,24.5) and used the slope formula to find the slope which was at -.42. After that I needed to find the equation so use the point slope formula to find it and it was y=-.42x+57.1. To find the correlation coefficient I needed to use the graphing calculator to find that r=-.99. Finding r is important since it tells the higher the speed you would drive, the the mileage would be. The line of best fit would be y=-.41x+56.92. To find the mileage for a speed of 55 miles per hour I had to plug the 55 into X to get 34.37. To find the speed if the mileage is 28 I needed to plug the 28 into Y to get -70.54.