Quick Answer:

The missing design could be:

Complete Solution:

One way to approach this problem is to examine the pattern of dots. In the first figure, there are four rows of horizontal dots in the pattern 1, 3, 3, 1. In the third figure, there are eight rows of dots in the pattern 1, 3, 5, 7, 7, 5, 3, 1. It seems logical, therefore, that the missing figure would include six rows of dots in the pattern 1, 3, 5, 5, 3, 1
[see pattern at left].

Another way to look at the pattern is to count the ”loops” in the design. The first figure has two loops per side, while the third figure has four loops per side. In this case, it seems reasonable for the missing figure to have three loops on each side.

A third way to consider the problem involves counting squares. The first design is a two-by-two square; the third is a six-by-six square. Therefore, the second might be a four-by-four square. pattern below so that every dot lies on at least one of the line segments.