The answer is 64 because it goes by 2 abd it needs to find the line between the boxes
A plot of residuals (vertical deviations from the regression line) shows the errors or lack of fit, so it would indicate a good fit if the residuals are small, vs. over fit if they are large. Due to age related growth short pre teen, and a plateau after age 21, I would expect a linear regression would offer estimate age 5.5 years.
Don't trust those link my guy
