The table shown to the right gives the national average pupil-leacher ratio in public schools over selected years. .- 3. Find the equation for the least squares line. Let x corr's'pond to the number of years since 1992 and let y correspond to the average number of , pupils per 1 teacher. e: 1992 b. Use the answer from part a to predict the pupilteacher ratio in 2020. Does this seem realistic? c. Calculate and interpret the correlation coeicient