Question

What's wrong with this code:
balance = 4213
annualInterestRate = 0.2
monthlyPaymentRate = 0.4
month = 1
balance = (balance - (balance*monthlyPaymentRate))*(1+(annualInterestRate/12))
while month < 13:
print "Month: " + str(month)
print "Minimum monthly payment: " + str(round(minimum_payment_rate, 2))
print "Remaining balance: " + str(round(balance, 2))
month += 1

Answer 1

you have your while loop not affecting the balance

Answer 2

Please explain

Answer 3

after "while month <=13" all you have are print statements
you are not using each month to alter the current balance

Answer 4

balance = (balance - (balance*monthlyPaymentRate))*(1+(annualInterestRate/12))

the way that you have your code you are only performing this operation once
i.e. you only make one payment

Answer 5

what you want to do is re-code this so that that operation happens each month

Answer 6

and minimum pay rate is not defined, as Python will tell you

Answer 7

You should be calculating the balance based off the payments you make in a 12 month period and then repeating this as you increase the payment to find the correct payment amount.

Answer 8

yes bro, that' the responds I get from python

Answer 9

well that's an easy one to fix
you have not defined the variable minimum_payment_rate at any point in the code
is this problem 1 or 2 in pset2 ?

Answer 10

pset1

Answer 11

yeah, so you need a formula for minimum_monthly_payment in terms of variables you have already defined

you have already written it earlier, you just need to identify it
what is the formula for minimum_monthly_payment ?

Answer 12

it is (Minimum monthly payment rate) x (Previous balance)

Answer 13

yeah, which you wrote already as...?

Answer 14

I don't think I have written it in my code

Answer 15

you don't see balance times monthly payment in your code?

Answer 16

yes I have written it in the balance = (balance - (balance*monthlyPaymentRate))*(1+(annualInterestRate/12)), if this is what you are asking for

Answer 17

yes

Answer 18

the variable you wrote to print, minimum_monthly_payment, is completely undefined in your code. you may as well have written
print purple_turtle
you just invented a variable
replace it with the stuff we have defined...

Answer 19

so I should remove the print statement of print "Minimum monthly payment: " + str(round(minimum_payment_rate, 2)) and replace it with print purple_turtle?

Answer 20

have we defined purple_turtle ?
no, my point is to replace it with something that you have defined
again (it's on the webpage with the problem) what is the formula for minimum monthly payment?

Answer 21

this is it (Minimum monthly payment rate) x (Previous balance)

Answer 22

and how did you code minimum monthly payment rate?

Answer 23

that's where my confusion comes in

Answer 24

you gave it a name, you called it
monthlyPaymentRate

that is probably more of a hint than I should have given you

Answer 25

are you saying that anywhere I see monthlyPayingRate I should replace it with purple_turtle.

Answer 26

no, I'm saying that where you see the \(undefined\) variable minimum_monthly_payment you should replace it with the \(defined\) variables monthlyPaymentRate*(something)
you're gonna have to figure out the something for yourself.

Answer 27

ok, I want to know how to make python understand the 'minimum_monthly_payment'

Answer 28

minimum_monthly_payment=balance*monthlyPaymentRate
that is all the help I'm going to give you since the deadline is still not up yet
your code has another issue, but you will have to deal with that one on your own.
Good luck!!