The processing of raw coal involves "washing," in which coal ash (nonorganic, incombustible material) is removed. The article "Quantifying Sampling Preash to the density of a coal particle. The average percentage ash for five densities of coal particles was measured. The data are presented in the following table:
Density (g/cm3 ) Percent ash
1.25 1.93
1.325 4.63
1.375 8.95
1.45 15.05
1.55 23.31
a. Construct a scatterplot of percent ash (y) versus density (x).
b. Compute the least-squares line for predicting percent ash from density.
c. If two coal particles differed in density by 0.1 g/cm3 , by how much would you predict their percent ash to differ?
d. Predict the percent ash for particles with density 1.40 g/cm3 .
e. Compute the fitted values.
f. Compute the residuals. Which point has the residual with the largest magnitude?
g. Compute the correlation between density and percent ash.