Here, our equation is 3/5 (0.6) mile per 1/4 (0.25) hour. 0.25 times 4 = 1, so we have to multiply 1/4 (0.25) 4 times to get 1 mile. To get a proportional answer, we must also multiply 3/5 (0.6) by 4. This comes out to 2.4. So her walking rate is 2.4 miles per hour.