Yes, 0.75 is a rational number. A rational number is defined as any number that can be expressed as the quotient or fraction of two integers, where the denominator is not zero.
In the case of 0.75, it can be represented as the fraction 75/100. When simplified, this fraction equals 3/4 which clearly shows that 0.75 can be expressed as a ratio of two integers (3 and 4). Because it fulfills the criteria of being expressible as a fraction with integer values, we classify 0.75 as a rational number.