Question

c) divide the width of the needle by the diameter of a red blood cell. in other words, divide your answer from (b) by your answer from (a). give your answer in standard notation. round to the nearest whole number.
d) which is the best interpretation of the number you found in part (c)?
○ the width of the needle is ___ meters longer than the diameter of a red blood cell.
○ the width of the needle is ___ times the diameter of a red blood cell.
○ the diameter of a red blood cell is ___ meters longer than the width of the needle.
○ the diameter of a red blood cell is ___ times the width of the needle.

Explanation:

Part (d)

We divided the width of the needle (from part b) by the diameter of a red blood cell (from part a). Division in this context represents how many times one quantity fits into another. So the result shows how many times the diameter of the red blood cell fits into the width of the needle, i.e., the width of the needle is that many times the diameter of the red blood cell. The other options are incorrect: we divided needle width by RBC diameter, not the reverse (so last option is out), and division here isn't about length difference (so first and third are out).

Answer:

The width of the needle is ___ times the diameter of a red blood cell.