Final answer:
A mystery cell that is 7500 nanometers is 7.5 micrometers in size. You divide the number of nanometers by 1,000 to convert to micrometers.
Step-by-step explanation:
To convert the size of the mystery cell from nanometers to micrometers, you need to know the conversion factor between these two units. One micrometer (μm) is equal to 1,000 nanometers (nm). So, you can convert the size of the cell by dividing its size in nanometers by 1,000.
Conversion: 7500 nm ÷ 1,000 = 7.5 μm
Therefore, a mystery cell that is 7500 nanometers big is 7.5 micrometers in size. For comparison, a typical human red blood cell is about 8 micrometers in diameter, which is slightly larger than the mystery cell. This helps to understand the scale of different cells commonly observed under light microscopes.