Roller coasters with larger heights usually go faster than shorter ones. Here is a scatterplot of x= height (in feet) versus y= maximum speed (in miles per hour) for a sample of 9 roller coasters. The equation of the regression line for this relationship is
y = 28.17 + 0.2143 x

Calculate and interpret the residual for the Iron Shark, which has a height of 100 feet and a top speed of 52 miles per hour.