weighted average of interest rate












0












$begingroup$


Let say that I have 2 loans. One loan has an interest rate of 5% and the other of 10%. I calculate the weighted average both loans and it is 8% (This is an example). I don't know how can you prove that the total interest yield of both loans with thier original interest rates is the same as if both loans interest rate was 8%. I don't know how to prove it. I would like some intuition.










share|cite|improve this question









$endgroup$












  • $begingroup$
    How do you calculate that the "weighted average of both loans" is 8^%? The only way I know to find such a weighted average is use the fact that "the total interest yield of both loans with their original interest rates is the same as if both loans interest rate was 8%." You don't need to prove it- that is the definition of "weighted average".
    $endgroup$
    – user247327
    Sep 25 '18 at 23:30










  • $begingroup$
    my confusion is for example, let say that loan 1 is a loan with a term of 60 month at 5% and that at the end the loan will yield 2000 in interest. Also Loan 2 is with term of 60 month at 7% and the loan will yield 2500. The balance of the loan does not matter my confusion y how can i be sure that using the weight average will yiled the same 4500 in interest. you know that the interest of a loan is not just multiplying the balance by the rate, there is an amortization process
    $endgroup$
    – kprincipe
    Sep 26 '18 at 0:22
















0












$begingroup$


Let say that I have 2 loans. One loan has an interest rate of 5% and the other of 10%. I calculate the weighted average both loans and it is 8% (This is an example). I don't know how can you prove that the total interest yield of both loans with thier original interest rates is the same as if both loans interest rate was 8%. I don't know how to prove it. I would like some intuition.










share|cite|improve this question









$endgroup$












  • $begingroup$
    How do you calculate that the "weighted average of both loans" is 8^%? The only way I know to find such a weighted average is use the fact that "the total interest yield of both loans with their original interest rates is the same as if both loans interest rate was 8%." You don't need to prove it- that is the definition of "weighted average".
    $endgroup$
    – user247327
    Sep 25 '18 at 23:30










  • $begingroup$
    my confusion is for example, let say that loan 1 is a loan with a term of 60 month at 5% and that at the end the loan will yield 2000 in interest. Also Loan 2 is with term of 60 month at 7% and the loan will yield 2500. The balance of the loan does not matter my confusion y how can i be sure that using the weight average will yiled the same 4500 in interest. you know that the interest of a loan is not just multiplying the balance by the rate, there is an amortization process
    $endgroup$
    – kprincipe
    Sep 26 '18 at 0:22














0












0








0





$begingroup$


Let say that I have 2 loans. One loan has an interest rate of 5% and the other of 10%. I calculate the weighted average both loans and it is 8% (This is an example). I don't know how can you prove that the total interest yield of both loans with thier original interest rates is the same as if both loans interest rate was 8%. I don't know how to prove it. I would like some intuition.










share|cite|improve this question









$endgroup$




Let say that I have 2 loans. One loan has an interest rate of 5% and the other of 10%. I calculate the weighted average both loans and it is 8% (This is an example). I don't know how can you prove that the total interest yield of both loans with thier original interest rates is the same as if both loans interest rate was 8%. I don't know how to prove it. I would like some intuition.







average






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Sep 25 '18 at 23:23









kprincipekprincipe

998




998












  • $begingroup$
    How do you calculate that the "weighted average of both loans" is 8^%? The only way I know to find such a weighted average is use the fact that "the total interest yield of both loans with their original interest rates is the same as if both loans interest rate was 8%." You don't need to prove it- that is the definition of "weighted average".
    $endgroup$
    – user247327
    Sep 25 '18 at 23:30










  • $begingroup$
    my confusion is for example, let say that loan 1 is a loan with a term of 60 month at 5% and that at the end the loan will yield 2000 in interest. Also Loan 2 is with term of 60 month at 7% and the loan will yield 2500. The balance of the loan does not matter my confusion y how can i be sure that using the weight average will yiled the same 4500 in interest. you know that the interest of a loan is not just multiplying the balance by the rate, there is an amortization process
    $endgroup$
    – kprincipe
    Sep 26 '18 at 0:22


















  • $begingroup$
    How do you calculate that the "weighted average of both loans" is 8^%? The only way I know to find such a weighted average is use the fact that "the total interest yield of both loans with their original interest rates is the same as if both loans interest rate was 8%." You don't need to prove it- that is the definition of "weighted average".
    $endgroup$
    – user247327
    Sep 25 '18 at 23:30










  • $begingroup$
    my confusion is for example, let say that loan 1 is a loan with a term of 60 month at 5% and that at the end the loan will yield 2000 in interest. Also Loan 2 is with term of 60 month at 7% and the loan will yield 2500. The balance of the loan does not matter my confusion y how can i be sure that using the weight average will yiled the same 4500 in interest. you know that the interest of a loan is not just multiplying the balance by the rate, there is an amortization process
    $endgroup$
    – kprincipe
    Sep 26 '18 at 0:22
















$begingroup$
How do you calculate that the "weighted average of both loans" is 8^%? The only way I know to find such a weighted average is use the fact that "the total interest yield of both loans with their original interest rates is the same as if both loans interest rate was 8%." You don't need to prove it- that is the definition of "weighted average".
$endgroup$
– user247327
Sep 25 '18 at 23:30




$begingroup$
How do you calculate that the "weighted average of both loans" is 8^%? The only way I know to find such a weighted average is use the fact that "the total interest yield of both loans with their original interest rates is the same as if both loans interest rate was 8%." You don't need to prove it- that is the definition of "weighted average".
$endgroup$
– user247327
Sep 25 '18 at 23:30












$begingroup$
my confusion is for example, let say that loan 1 is a loan with a term of 60 month at 5% and that at the end the loan will yield 2000 in interest. Also Loan 2 is with term of 60 month at 7% and the loan will yield 2500. The balance of the loan does not matter my confusion y how can i be sure that using the weight average will yiled the same 4500 in interest. you know that the interest of a loan is not just multiplying the balance by the rate, there is an amortization process
$endgroup$
– kprincipe
Sep 26 '18 at 0:22




$begingroup$
my confusion is for example, let say that loan 1 is a loan with a term of 60 month at 5% and that at the end the loan will yield 2000 in interest. Also Loan 2 is with term of 60 month at 7% and the loan will yield 2500. The balance of the loan does not matter my confusion y how can i be sure that using the weight average will yiled the same 4500 in interest. you know that the interest of a loan is not just multiplying the balance by the rate, there is an amortization process
$endgroup$
– kprincipe
Sep 26 '18 at 0:22










1 Answer
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$begingroup$

Set the interests equal to each other to figure the relative size of the loans.



$.08x + .08y = .05x + .10y$



$.03x = .02y$



$x = frac{2}{3}y$



Therefore the $x$ loan is $frac{2}{3}$ of the $y$ loan.



Example:



$x = 600; y = 900$



$.08x + .08y = .05x + .10y$



$.08(600) + .08(900) = .05(600) + .10(900)$



$48 + 72 = 30 + 90$



$120 = 120$






share|cite|improve this answer









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    $begingroup$

    Set the interests equal to each other to figure the relative size of the loans.



    $.08x + .08y = .05x + .10y$



    $.03x = .02y$



    $x = frac{2}{3}y$



    Therefore the $x$ loan is $frac{2}{3}$ of the $y$ loan.



    Example:



    $x = 600; y = 900$



    $.08x + .08y = .05x + .10y$



    $.08(600) + .08(900) = .05(600) + .10(900)$



    $48 + 72 = 30 + 90$



    $120 = 120$






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      Set the interests equal to each other to figure the relative size of the loans.



      $.08x + .08y = .05x + .10y$



      $.03x = .02y$



      $x = frac{2}{3}y$



      Therefore the $x$ loan is $frac{2}{3}$ of the $y$ loan.



      Example:



      $x = 600; y = 900$



      $.08x + .08y = .05x + .10y$



      $.08(600) + .08(900) = .05(600) + .10(900)$



      $48 + 72 = 30 + 90$



      $120 = 120$






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        Set the interests equal to each other to figure the relative size of the loans.



        $.08x + .08y = .05x + .10y$



        $.03x = .02y$



        $x = frac{2}{3}y$



        Therefore the $x$ loan is $frac{2}{3}$ of the $y$ loan.



        Example:



        $x = 600; y = 900$



        $.08x + .08y = .05x + .10y$



        $.08(600) + .08(900) = .05(600) + .10(900)$



        $48 + 72 = 30 + 90$



        $120 = 120$






        share|cite|improve this answer









        $endgroup$



        Set the interests equal to each other to figure the relative size of the loans.



        $.08x + .08y = .05x + .10y$



        $.03x = .02y$



        $x = frac{2}{3}y$



        Therefore the $x$ loan is $frac{2}{3}$ of the $y$ loan.



        Example:



        $x = 600; y = 900$



        $.08x + .08y = .05x + .10y$



        $.08(600) + .08(900) = .05(600) + .10(900)$



        $48 + 72 = 30 + 90$



        $120 = 120$







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Sep 25 '18 at 23:37









        Phil HPhil H

        4,2482312




        4,2482312






























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