Pelomyxa palustris is an amoeba with a length of 4.9 mm. Amoeba proteus has a length of 0.7 mm. How many amoeba proteus would you have to line up to equal the length of three pelomyxa palustris?

21

Step-by-step explanation:

Let n represent the number we're looking for. Then ...

n * (proteus length) = 3 * (palustris length)

n * 0.7 mm = 3 * 4.9 mm

n = (3 * 4.9 mm) / (0.7 mm) = 3 * 49/7 = 3 * 7

n = 21

You would have to line up 21 amoeba proteus to equal the length of three pelomyxa palustris.