Residual candy Data were collected on a sample of 12 brands of movie candy. The scatterplot shows the rela- tionship between x = amount of sugar (in grams) and y = number of calories, along with the least-squares regression line. The standard deviation of the residuals for this model is s = 105.5. Interpret this value.

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.