24
ON THE VALUE OF ANNUITIES.
By logarithms,
log 1.05~* = 1.9788101
10
log 1.05-“ - 1.7881070
log s “ 2.5440680
2.3321750 = 214.870 = £214 17 5
In the expression (1 + ¿)~" if i be taken = .02 and 1, 2,3,
&c. respectively, the several values which it represents will be expressed
by the geometrical series 1.02~ *, 1.02~ 2 , 1.02“ 3 , &c., which numbers
respectively denote the reciprocals of the amounts of £l at 2 per cent,
in 1, 2, 3, &c. years, the decimal values of which being found, furnish
a table of the present values of £l at 2 per cent; when i is equal to
.025, .03, .35, &c., and the decimal values are found, the series will
give the present values of £l at 2-?, 3, 3j, &c. per cent. Tables of the
present values of £l due at the expiration of any number of years not
exceeding 100, were calculated by Mr. Smart at the rates of 2, 2^, 3,
3^, 4, 4i, 5, 6, 7, 8, 9, and 10 per cent, to 8 figures of decimals, and
published in his valuable collection of Tables; they have been copied
from thence, and given in Table 4 of this work, with the whole of the
decimals, which will be found useful where great accuracy is required.
36. To find (s) the sum due,
(Art. 35.)
(1 + 0“
Multiplying each side by (1 + i) n (Arith. and Alg., 110.)
V (1 + i T-
By logarithms, log s — logp + w.log (1 + i)
Rule. Multiply the present value by the amount of £l in the given
time.
Example. What sum will the present payment of £214.87 entitle
a person to at the expiration of 10years, compound interest 5 per cent?
n — 10
1.628894
78.412 “ p inverted
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