Not getting expected output on program

[Dryeye]

I can't seem to get the expected out for the following program:

Summary

Interest on a credit card’s unpaid balance is calculated using the average daily balance.

Suppose that netBalance is the balance shown in the bill, payment is the payment made, d1 is the number of days in the billing cycle, and d2 is the number of days payment is made before billing cycle.

Then, the average daily balance is:

averageDailyBalance = (netBalance * d1 – payment * d2) / d1

If the interest rate per month is, say, 0.0152, then the interest on the unpaid balance is:

interest = averageDailyBalance * 0.0152

Instructions

Write a program that accepts as input netBalance, d1, payment, d2, and interest rate per month (interestRate).

The program outputs the interest.

Format your output to two decimal places.
Grading

When you have completed your program, click the Submit button to record your score.

this is my code:

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
// Write your main here
double netBalance,d1,payment,interest,d2,interestRate,averageDailyBalance;

cout << setprecision(2) << fixed << showpoint;
cout << "Enter net Balance: ";
cin >> netBalance;
cout << "Enter payment made: ";
cin >> payment;
cout << "Enter number of days in the billing cycle: ";
cin >> d1;
cout << "Enter number of days payment is made before billing cycle: ";
cin >> d2;
cout << "Enter interest per month: ";
cin >> interestRate;

averageDailyBalance = (netBalance * d1 - payment * d2)/d1;
interest = averageDailyBalance * interestRate;

cout <<endl<< "Interest is " << interest << endl;
return 0;
}


Input:
100
30
50
7
9.7
expected output: 856.26
my output: 929.26

Input
255.76
31
55
3
12.3
expected output 3080.38
my output: 3125.05

[jonnin]

is there any chance you confused which input is which here?
also, humans know that interest is a %
that is, 9.7 % of 100 is (100*0.097) = 9.7 ....
your math is right, but should you have typed 0.097??

your code is fine. I suspect the problem is the data.

also, the answer will be different if you round or trunc each part to 2 decimals vs round at the end. Unclear which you want here (usually round / trunc at the last step is right).

finally, double check the expected output by hand. Can you get it with a calculator?

[Dryeye]

I got the input values from the Test Case provided by Cengage|Mindtap.

I have also tried 0.097 instead of 9.7 but I still don't get the expected output for the test case.

I am wondering If I am missing an equation or did I type the equation wrong.

[Dryeye]

I figured it out.

instead of using the equation provided which was:

averageDailyBalance = (netBalance * d1 - payment * d2)/d1;

I switch things up in the equation, and the equation that worked was:

averageDailyBalance = (netBalance * payment - d1* d2)/payment;

CENGAGE|MINDTAP gives the input but does tell which number belongs to which input.

Thank you jonnin for your reply.