We let x be the initial amount of money and r be the rate of interest (already in decimal) such that the equation for the future worth of money is, after two years, F = 44100 = x(1 + r)^2 after four years, F = 48620.25 = x(1 + r)^4 Solving for the values of x and r in the equation will give us answers of 40,000 and 0.05, respectively. Thus, the interest rate is approximately 5%.
The word "similar" from a math standpoint means to express proportionality. So long as two shapes have proportional sides, the exact lengths do not have to be equal. However, the angles need to be the same.