Question

I need help writing a c++ program

Answer 1

The monthly payment on loan may be calculated by the following formula:


Payment = Rate * (1 + Rate)^N
------------------- * L
((1 + Rate)^N - 1)

Rate is the monthly interest rate, which is the annual interest rate divided by 12.
N is the number of payments and L is the amount of the loan. Write a program that asks
for these values an displays a report similar to.

Loan amount: $ 10000.00
Yearly Interest rate: 1%
Number of Payments: 36
Monthly Payment: $ 332.14
Amount Paid Back: $ 11957.15
Interest Paid: $ 1957.15

Answer 2

#include <iostream>;
#include <iomanip>;
#include <string>
#include <cmath>
using namespace std;

int main()
{
int yearRate, numbPay;
double loan, monthPay, paidBack, interest, rate;

cout << setprecision(2) << fixed;
//gets loan amount,
cout << "Enter the loan amount => ";
cin >> loan;
//gets yearly interest rate
cout <<"Enter the yearly interest rate as a percentage => ";
cin >> yearRate;
//gets number of payments
cout << "Enter the number of payments ";
cin >> numbPay;

//calculates Monthly Payment, Amount Paid back, and Interest Paid
rate = yearRate / 12.0 + 1;
monthPay = (( rate * pow((1+rate),numbPay)) / ( pow((1+rate),numbPay) - 1 ) ) * loan;
paidBack = monthPay * numbPay;
interest = paidBack - loan;

//outputs the loan, yearRate, numbPay, monthPay, paidBack, and interest variables
cout << "Loan Amount: $ " << loan << endl;
cout << "Yearly Interest Rate: " << yearRate << "%" << endl;
cout << "Number of Payments: " << numbPay << endl;
cout << "Monthly Payment: $ " << monthPay << endl;
cout << "Amount Paid Back: $ " << paidBack << endl;
cout << "Interest Rate: $ " << interest;

//this is just to show what rate is for testing purposes
cout << "\n\nthis is rate " << rate;



//option to end program
cin.ignore();
cout << "\nPress enter to end";
cin.get();
return 0;
}

Answer 3

monthPay = (( rate * pow((1+rate),numbPay)) / ( pow((1+rate),numbPay) - 1 ) ) * loan;
I believe the error is here

Answer 4

What is the error?

Answer 5

the values don't come out there supposed to when I put them in the program

Answer 6

here is a sample functioning compiled version that the instructor gave for reference

Answer 7

You should probably have a variable just to store `pow((1+rate),numbPay)` so that you don't call it twice.

Answer 8

`rate = yearRate / 12.0 + 1;` why are you adding `1` to this twice?

Answer 9

oh i, i don't now, looks like an error

Answer 10

fixed it

Answer 11

the instructor said to make the formula be in one cpp statement

Answer 12

ok

Answer 13

what is next?

Answer 14

well do u know what i mean by getting the wrong values that come out of the program

Answer 15

Yes

Answer 16

Is it still not working?

Answer 17

well run the source and put 5 in all input, then run the exe i posted and put the same input. u get completely different results

Answer 18

i think im messing up in the line 25 area

Answer 19

what should you get and what do you get?

Answer 20

when i put 5 in for the exe i get monthly payment = 1.01, amount paid back = 5.06, and interest paid= .06

Answer 21

show all output for correct and your program.

Answer 22

for the source i get 2.53, 12.63, and 7.65, respectively

Answer 23

the correct is the exe

Answer 24

Sorry, I'm not going to run some random .exe. I don't trust it.

Answer 25

who even said I was on windows?

Answer 26

umm noone, im saying the exe results i posted just now are the right ones

Answer 27

and the source from my code are incorrect

Answer 28

What is input?

Answer 29

it's what i type the console prompt

Answer 30

.....

Answer 31

.....

Answer 32

why is yearly interest rate an `int`?

Answer 33

because it's a percentage which isn't ussually a fraction for interest, also i don't wasn't there
to be two zeros after it like the double's do due to the setprecision(2)

Answer 34

*want

Answer 35

But the formula requires you use a decimal, not a percent.

Answer 36

no, the formula dosen,t even use yearly interest rate, it uses monthly interest rate, which is found using "yearly rate / 12"

Answer 37

If the yearly rate is 12 for 12%, then monthly rate would be 1, but that is the decimal equivalent of 100%.

Answer 38

You are confusing the hell out of the computer, because you are giving it a rate that is off by 100.

Answer 39

dude there are 12 months in a year, the % has nothing to do with the value of the monthly or yearly, it's just a symbol put to show that it's interest

Answer 40

\[
1000 \times 50\% \neq 1000 \times 50
\]

Answer 41

i agree, i still don't see ur point

Answer 42

Loan amount: $ 5.00
Yearly Interest rate: 5%
Number of Payments: 5
Monthly Payment: $ 1.01
Amount Paid Back: $ 5.06
Interest Paid: $ 0.06

Answer 43

ignore the earlier comment about
Loan amount: $ 10000.00
Yearly Interest rate: 1%
Number of Payments: 36
Monthly Payment: $ 332.14
Amount Paid Back: $ 11957.15
Interest Paid: $ 1957.15

Answer 44

i messed up copying from the exe

Answer 45

just use this as reference for what the program does
Loan amount: $ 5.00
Yearly Interest rate: 5%
Number of Payments: 5
Monthly Payment: $ 1.01
Amount Paid Back: $ 5.06
Interest Paid: $ 0.06

Answer 46

Okay let me make it really clear for you....

`int yearRate`
`cin >> yearRate;`
At this point, `yearRate` has to be an integer like 5 or something.

`rate = yearRate / 12.0;`
At this point `rate` will be 5/12, which equals about 0.41

`monthPay = (( rate * pow((1+rate),numbPay)) / ( pow((1+rate),numbPay) - 1 ) ) * loan;`
At this point, 0.41 is interpreted as 41%, not as 0.41% as it should be.

Answer 47

That is why your output is so huge.

Answer 48

well how do u fix it?

Answer 49

How do you think you fix it? Your number is 100 times too large.

Answer 50

/100

Answer 51

so i should fix it when im assigning a value to rate, correct?

Answer 52

yes

Answer 53

just hurry up and try it out. divide by 100

Answer 54

so yearRate/1200 ill see if it works

Answer 55

HOOOOLLEEEHH SHEEEET, it worked

Answer 56

thx