0.4375 is a fraction. It is a fraction in decimal form rather than in the form of a ratio. However, that does not stop it being a fraction. Its rational equivalent is 4375/10000 which can be simplified. But simplification will mean that you lose information about the precision of the fraction.
It is simply 4375/1 as an improper fraction
4375/1.
4375/10000 or 7/16
7/ 16
4375/1000
4375/1000
7/16
4.375 = 4375/1000 or 35/8 in fraction
7/16
4375/1000 or 35/8= 4.375 * 1000/1000= 4375/1000 or 35/8
4.37500 = 4375 / 1000 = 35 / 8
437.5 = 4375/10 = 875/2