複利息計算...急急急

你條式OK, 小心R是利息率 in decimal form, 不是 in %, 年利率16%, R 是 0.16, 香港貨幣是 dollar and cent, 所以 round off to 2 decimal places .$47415.86, 不是47415.8601

A =本利和 ??
P = 本 ($45000)
R = 年利率是in decimal form, R = 0.16
T = 存款時期 (n = 4/3 = 1.333333333)
n = 每年計算複利息多少次, (n = 4, 每年計算複利息四次,12/3 = 4)

A = P(1 +R/n)^T
A = $45000(1 +0.16/4)^1.333333333
A = $45000(1.04)^1.333333333 = $45000(1.05368578) = $47415.86

另一個例子:
把$45000存入銀行, 年利率16%, 每月計算複利息一次, 兩年後的本利和為多少?
A =本利和
P = 本 ($45000)
R = 年利息率 16% , R = 0.16
T = 存款時期 (n = 24, 兩年有24月)
n = 12, 每年計算複利息12次,12/1 = 12)
A = P(1 +R/n)^T
A = $45000(1 +0.16/12)^24
A = $45000(1.013333333)^24 = $45000(1.374218824) = $61839.85

Keep as many decimals as possible, only round off to 2 decimal in the final result.

n =1, 每年計算複利息1次
n = 2, 每半年計算複利息
n = 4, 每季計算複利息
n = 12, 每月計算複利息
n = 365, 每日計算複利息

T = 存款時期,
每年計息, T是存多少年 (存三個月, T = 0.25)
每半年計息, T是存多個半年 (存三個月, T = 0.5)
每季計息, T是存多少季(存兩年, T = 8)
每月計息, T是存多個月(存半年, T = 6)
每日計息, T是存多少日(存一年, T = 365)





2011-06-20 07:30:10 補充：
方程式是:
R% = n* [(A/P)^(1/T) – 1]*100

Example:
R% = 4* [(47415.86/ 45000)^[1/(4/3)] – 1]*100
R% = 4* 1.053685778^0.75– 1]*100
R% = 4* 1.053685778^0.75– 1]*100
R% = 4* 0.04 *100
R% = 16%

2011-06-20 07:35:45 補充：
方程式列明步驟:
A = P(1 +R/n)^T
A/P = (1 +R/n)^T
(A/P)^1/T = (1 +R/n)
(A/P)^1/T - 1 = R/n
R = n * [(A/P)^1/T – 1]
R% = n * [(A/P)^1/T – 1] * 100