In cases like these, you simply have to multiply the choices you have for each step.
In fact, you can choose between 4 different crusts. For each of these crusts you can choose 4 different sauces. This means that there are 
choices at this point. In fact, if we call the crust options 1,2,3,4 and the sauce options A,B,C,D, the 16 possible combinations are
From here, you keep going multiplying the number of options for each step, for a total of
In a dot plot, each one of the dots represents a value in the data set. When there are multiple values at a particular number, the dots just get stacked on top of each other. Using the dots in the plot, you can find the mean, median, mode or any other statistic that you need to summarize the data.
3 < x < 13
This is because the sum of two sides must be greater than the length of the third side.
