A pancake recipe calls for 1/4 of a cup of powdered milk and 2/3 cups of whole wheat flour for each batch of pancakes. If Ruby plans on making 4 batches of pancakes, how many combined cups of powdered milk and whole wheat flour does she need?
For 4 batches, Ruby will use 4 * 1/4 = <<4*1/4=1>>1 cup of powdered milk.
For the same 4 batches, Ruby will use 4 * 2/3 = <<4*2/3=8/3=2.67>>2.67 cups of whole wheat flour.
Therefore, Ruby needs a total of 1 + 2.67 = <<1+2.67=3.67>>3.67 cups of powdered milk and whole wheat flour. Answer: \boxed{3.67}.