3.75 equal how many inches?

Answer 1

You may want to consider whether this question was asked as intented. The number

3.75 is a unitless number so 3.75 without a unit such as feet or yards or centimeters

CANNOT be converted to inches. Could you have meant 3.75 inches. That's 3.75 inches which can be written as 3 and 3/4 inches. Could you have meant to say

3.75 feet? That would be 3.75 feet x [12 inches/ 1 foot] = 45 inches.

However, 3.75, not accompanied by a length unit cannot be converted to inches.

If it is a length, it could be 3.75 inches, 3.75 feet, 3.75 yards, 3.75 miles, or 3.75 millimeters 3.75 microns or 3.75 light years. All of these could be converted to inches and would have vastly different magnitudes.