## Tuesday, November 9, 2010

### CH 2. Project- Nissan GTR

Nissan GTR

For the chapter 2 project, I did it on the Nissan GTR. I used the speeds 55,60,65,70,75, and 80 the mileage (miles per gallon) are 21,20.4,19.3,17.4,16.2, and 15.1. Next, I plotted the points of a graph. For the independent variable, it was speed (miles per hour) and for the dependent variable, it was mileage (miles per gallon). As I graphed the data, it started to become a negative correlation. Then I drew the line of best fit and to find the slope, I used the two points (55,21) and (80,15.1). The slope I found was -5.9/35. When I used the point slope form, I found the equation y=-5.9x/35+11.73. When I used a graphing calculator to find the value of my graph's correlation coefficient of r was -.99 . The value of r tells us that the higher the speed is, the lower the mileage. The line of best fit equation I found with the calculator is y=-.25x+35.2. To predict the mileage for a speed of 55 miles per hour would be 21.45. To predict the speed if the mileage is 28 miles per gallon would be 28.8.