Mike and Julie are making slime. The table shows the number of drops of blue food coloring and the number of drops of red food coloring they use in each batch Drops of Food Coloring Number of blue drops Number of red drops 20 4 40 8 60 12 80 16 What is the constant of proportionality of the ratio of the number of blue drops used to the number of red drops used? 0.2 0.5 2 5