Madison is writing a report on the human body for science class. She wants to use numbers in exponent form for her report. She is having trouble deciding which format would be best for the diameter of a red blood cell: 7.5 x 104 mm or 7.5 x 10-4 mm. Help Madison decide which one to use. Compare and contrast these numbers to justify your choice. Be sure to include an explanation of the meaning of the negative exponent and the standard form for both of these numbers.