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A loan scehdule can be used to determine the outstanding balance of a loan. A loan schedule consists of two components:

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  1. interest component
  2. \n
  3. repayment component
  4. \n
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The total number of payments is the number of payments in one year multiplied by the number of years.

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total number of payments= $np$

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where:

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In the above question, substituting in $n$={n} and $p$={p} will give the total number of payments.

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As we know the value of the loan and that the repayment each period is like an annuity, we know that the present value of the annuity multipled by the number of periods in a year will give the value of the loan (see Numbas- Annuities PV).

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$px{a}_{n|}^{p}=loan$

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where:

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Re-arranging the above:

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$x={loan \\over p{a}_{n|}^{p}}$

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In the above question, working out ${a}_{n|}^{p}$ with an effective interest rate of {interest}% and substituting in loan=£{value} and $p$={p} will give the value of each payment.

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The outstanding balance, OB, is the value of the loan after a number of payments have been made. This can be calculated by creating a table with the interest and repayment component of each payment and then reading off the table. Another way would be to use the prospective method. This is the value of the remaining payments after $m$ payments have already been made.

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OB after the $m^{th}$ payment=$px{a}_{n-{m \\over p}|}^{(p)}$

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where:

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Working out ${a}_{n-{m \\over p}|}^{(p)}$ with an effective interest rate of {interest}% and substituting in $p$={p}, $m$={m}, $n$={n} and $x$ from the previous part will give the OB after the {m}th payment. 

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To work out the interest component of the $r^{th}$ payment, you first need to calculate the OB after the $(r-1)^{th}$ payment and then work out the interest on that value.

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OB after the $(r-1)^{th}$ payment=$px{a}_{n-{(r-1) \\over p}|}^{(p)}$

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As the payments are made every period, the interest component is found by multiplying $px{a}_{n-{(r-1) \\over p}|}^{(p)}$ by $i_{[p]}$.

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The interest component of the $r^{th}$ is:

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$i_{[p]}px{a}_{n-{(r-1) \\over p}|}^{(p)}$

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where:

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Working out ${a}_{n-{(r-1) \\over p}|}^{(p)}$ with an effective interest rate of {interest}% and $i_{[p]}$ and substituting in $p$={p}, $r$={r}, $n$={n} and $x$ will give the  interest component of the {r}th payment.

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The repayment component of the $s^{th}$ payment can be foound by subtracting the interest component of the $s^{th}$ payment from the payment per period. The interest component of the $s^{th}$ payment is found using the same method as above.

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The repayment component of the $s^{th}$ payment is:

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$x-i_{[p]}px{a}_{n-{(s-1) \\over p}|}^{(p)}$

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where:

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Working out ${a}_{n-{(s-1) \\over p}|}^{(p)}$ with an effective interest rate of {interest}% and $i_{[p]}$ and substituting in $p$={p}, $s$={s}, $n$={n} and $x$ will give the repayment component of the {s}th payment.

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How many payments are there in total?

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What is the value (to two decimal places) of each payment?

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What is the outstanding balance (to two decimal places) immediately after the {m}th payment?

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What is the interest component (to two decimal places) of the {r}th payment?

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What is the repayment component (to two decimal places) of the {s}th payment?

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What is the sum (to two decimal places) of the outstanding balances from the {x}th to the {y}th payment?

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You have not given your answer to two decimal places.

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What is the sum (to two decimal places) of the interest components from the {t}th to the {u}th payment?

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You have not given your answer to two decimal places.

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Suppose you borrow £{value} to be repaid in equal installments {p} times a year in arrears over a period of {n} years at an AER of {interest}%.

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Construct an Excel spreadsheet (using either the formulas derived in lectures or the Excel financial functions) presenting a loan schedule showing the interest and repayment component of every payment and the outstanding balance.

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Do the question in Excel first and then input the numbers.
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