Mathpow难度

Question

When I enter 1000 for investment amount 4.25 for monthly interest rate and 1 for years, why do I get the result 4.384414858452464E11 instead of the expected 1043.34?

import java.util.Scanner;

public class FinancialApplicationFutureInvestment_13 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("Enter investment amount: ");
        int investmentAmount = input.nextInt();
        System.out.println("Enter monthly interest rate: ");
        double monthlyInterestRate = input.nextDouble();
        System.out.println("Enter number of years");
        int numOfYears = input.nextInt();

        double futureInvestmentValue = investmentAmount *
            (Math.pow(1 + monthlyInterestRate, numOfYears * 12));
        System.out.println("Accumulated value is: " + futureInvestmentValue);

        double test = Math.pow(1 + monthlyInterestRate, numOfYears * 12);
        System.out.println(test);
    }
}

Answer 1

每月利率可能需要输入为0.0425

Answer 2

1 + monthlyInterestRate

Is monthlyInterestRate a raw factor, or is it expressed in percentage points?

Try dividing by one hundred.

Answer 3

the formula is

A = P(1+r/100)^n

so it should be

investmentAmount * (Math.pow(1 + (monthlyInterestRate/100), numOfYears * 12));

Answer 4

好吧，您将1 + 4.25（5.25）计算为每月利率，而不是1+（4.25 / 100）。

Answer 5

您应该在System.out.println中使用强制转换（双精度为int）-（int）（futureInvestmentValue * 100）/ 100.0