Can random samples and proportional reasoning be used to determine precise information about a population? explain

Find the area of the unshaded square

The roots of the function f(x) = x2 – 2x – 3 are shown. what is the missing number?

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.