As per the question the distance travelled by a car is 28.4 inch.
we are asked to determine the conversion factor in centimeter which when multiplied with 28.4 inch will give a unit.
we know that one inch =2.54 centimeter.
Hence 28.4 inch = 2.54 ×28.4 cm
=72.136 cm.
Now we have to determine the conversion factor .The multiplication factor is calculated as

[p is the multiplication factor.]
Hence the multiplication factor is 72.137 cm which will give unit conversion when multiplied with 28.4 inch.