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to the given rate per cent. for quarterly or half yearly payments, will be the true amount.

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The construction of

this table is from an Algebraic Theorem given by the learned Mons. De Moivre, in his Treatise of Annuities on Lives, which in words is thus: For half yearly payments take a unit from the ratio, and from the square root of the ratio, half the quotient of the first remainder, divided by the

latter will be the tabular

number; for quarterly payments, use the fourth root, as above, and take one-fourth of the quotient.

annum?

1. What will an annuity of $200 amount to in 5 years, to be paid in half yearly payments, at 6 per cent. per Ans. $1144 8c. 2m. + Agreeably to table first, the tabular number is 5.63709 × 200 $1127 41c. 8m. x 1.014781, (tabular number answering to 6 per cent. in table second, for half yearly payments,) $1144.08.2m. + answer.

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2. What will an annuity of $500 amount to in 5 years, at 6 cent.? per Ans. $2818.54.6 +. 3. What will an annuity of $1000, payable yearly, amount to in 10 years? Ans. $13180.79.4+. 4. What will annuity of $30, payable yearly, amount Ans. $95.50.8+.

to in 3 years?

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0,952381

0,943396 14 9,898641

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ANNUITIES.

Table Third, shewing the present worth of an Annuity of $1, from One year to Thirty-seven.

cent. 6 per cent. Yrs. 5 per cent. 6 per cent. Yrs. 5 per cent. 6 per cent.

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3,545950 3,465106

16 10,83770 10,105895 28 11,27406610,477260 29

13,406164

15,14107413,590721

4,329477 4,212364

1811,689587 10,827603 30

15,372451

13,764831

5,075692

4,917324 19 12,08532111,158116 5,786373 5,582381 20 12,462216 11,469921

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8

6,463213

6,209794

12,82115311,764077

3316,002549 14,230230

9

7,107822 6,801692

2213,16300312,041582

34

16,19290414,368141

10

7,721735 7,360087

11

2313,48857412,303379

35 16,374194 14,498246.

8,306414 7,886875 24 13,798642 12,550358 36 16,546852 14,620987 12 8,863252 8,388844 25 14,093945 12,783356 37 16,711287 14,736780 13 9,393573 8,852683 2614,375185 | 13,003166

EXPLANATION OF THE TABLE.

What is the present worth of $1, to continue for 4

years at 6 per cent. per annum? Ans. 3.465106, agree

ing with the tabular number opposite to 4 years at 6 per cent. per annum.

First, find the present worth of $1, by discount for 1 year at 6 per ct. per annum, which is

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$0.943396

0.889996

0.839619

0.792094

$3.465105

Tabular number for 4 years at 6 per. cent. as in table 3d. 1. What is the present worth of $50 per annum for 6 years at 6 per cent. per annum? Ans. $245.86c. 6m.

CASE III.

Annuities in Reversion.

The annuity, time, and rate given, to find the present worth as in case 2. Multiply the number, under the rate and opposite th etime in table 3d, by the annuity, the product will be the present worth for yearly payments. If the payments are to be made half-yearly, or quarterly, the present worth so found for yearly payments, must be multiplied by the proper number in table 2d.

Q. What is meant by annuities in reversion?

A. Sums of money, which are paid yearly for a limited period, but which do not commence till after the expiration of a given period, are called annuities in reversion. Given the time of reversion, time of continuance and rate per cent. to find the present worth of the reversion. RULE. Take two numbers under the given rate in table 3, corresponding to the different periods of time, viz; time of reversion and time of continuance, and take the difference between the tabular numbers, answering to the times as above mentioned, and multiply that difference by the

annuity, for the present worth annually, if the payments be half yearly or quarterly, we must use table 2 as above stated.

1. The reversion of a freehold is $60 per annum for 4 years, to commence 2 years hence, what is the present worth, allowing 6 per cent. for prompt payment.

Illustration.-Time of continuance 6 years.

Tabular number for 6 years at 6 per cent. found in table 3, is

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4.917324

Time of reversion; 2 years tabular No. 1.833393

3.083931x60 =

$185.03c.5m. × Answer.

3.083931

2. What is the present worth of a reversion of a lease of $100 per annum, to continue 10 years; but is not to commence till the end of 2 years at 6 per cent.

Ans. $655.04.

3. What is the present worth of a reversion of a lease for $120 per annum to continue 9 years, but not to commence till the end of 4 years at 5 per cent. to the purchaser? Ans. $701.71c. 4m.

PERPETUITIES.

Annuities which continue for ever, are called perpetu

ities.

CASE IV.

Given the Annuity and rate per cent. to find the present

worth,

RULE. Divide the annuity by the ratio less 1, for the present worth.

Note.-Table 2d must be resorted to, as in temporary annuities, when the payments are half-yearly or quarterly. 1. What is the present worth of an annuity of $150 to continue for ever, allowing 5 per cent. to the purchaser? Operation.-1.05—1 = .05)150.00

$3000 Ans.

244

COMPOUND INTEREST.

ALLIGATION.

2. What is an estate of $260 per annum, to continne for ever, worth in present money, allowing 6 per cent. to the purchaser? Ans. $4333.33.3 +. 3. A property in fee simple rents for $120 per annum, what is the present worth, allowing 5 per cent. to the purchaser? Ans. $2400.

DISCOUNT BY COMPOUND INTEREST.

The ratio in compound interest is the amount of $1 for one year, which is found thus: as 100: 106: : 1 = $1.06 is the amount of $1 for one year.

Example 1.-What is the present worth of 600 for 3 years; hence at 6 per cent. compound interest 1.063 = 1.191016)600( $503.77+ Ans.

=

2. What is the amount of $503.77, in 3 years at 6 per cent.? Ans. $600. 3. What is the present worth of $520, due 5 years hence, at 6 per cent. compound interest. Here 520 =

1,3312256)520(-390.62 answer.

ALLIGATION,

1.065

From the Latin (ad. to, and ligo to bind,) it being necessary in sundry cases to link or bind the quantities.

We shall not omit the rule of Alligation, the object of which is to find the value of several things of the same kind of different values. The following examples will sufficiently demonstrate it.

CASE I.

When the quantities and rates of the simples are given to find the rate of a mixture compounded of these simples. RULE.--Find the value of each quantity, according to their respective costs, then divide the sum of the pro

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