An experiment is conducted to determine the relationship between initial speed and stopping distance of automobiles. A sample of twelve cars is tested and the following data are recorded:
Initial speed in mph (x) 20 20 30 30 40 40 50 50 60 60 70 70
Stopping distance in ft (y) 15.9 24 41.2 58.7 74.8 88.8 112.6 127.6 216.4 200 276.8 301
1. Draw the scatterplot of this data. Observe that the shape is not linear. How can you best describe the shape?
2. Create a new set of data using the transformation y' = sqrt(y). In other in the above table keep the x values the same and replace the y values by y' values.
3. Draw a scatterplot of this data. What can you say about the shape of this scatterplot?
4. Find the linear equation that best describes the relationship between x and y'
5. Replace the y' in this equation by sqrt(y) and solve the resulting equation for y.
6. Write a brief conclusion.