is -0.071625 a rational number?

Yes, -0.071625 is a rational number. A rational number is any number that can be expressed as the quotient or fraction of two integers, where the denominator is not zero. In this case, -0.071625 can be written as the fraction -71625/1000000, and since -71625 and 1000000 are both integers, -0.071625 is rational.