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.