[TI-nspire] irr, mirr 내부수익률, 수정된 내부수익률 의 계산

irr(CF0,CFList [,CFFreq]) ⇒ value

Financial function that calculates internal rate of return of an investment.

• CF0 is the initial cash flow at time 0; it must be a real number. 
• CFList is a list of cash flow amounts after the initial cash flow CF0.
• CFFreq is an optional list in which each element specifies the frequency of occurrence for a grouped (consecutive) cash flow amount, which is the corresponding element of CFList. The default is 1; if you enter values, they must be positive integers <10,000.

mirr(financeRate,reinvestRate,CF0,CFList[,CFFreq])

Financial function that returns the modified internal rate of return of an investment.

• financeRate is the interest rate that you pay on the cash flow amounts.
• reinvestRate is the interest rate at which the cash flows are reinvested.
• CF0 is the initial cash flow at time 0; it must be a real number.
• CFList is a list of cash flow amounts after the initial cash flow CF0.
• CFFreq is an optional list in which each element specifies the frequency of occurrence for a grouped (consecutive) cash flow amount, which is the corresponding element of CFList. The default is 1; if you enter values, they must be positive integers < 10,000. 

• CF0 = - 200,000 (초기 투자액)
• CF1 = 20,000
• CF2 = 25,000
• CF3 = 30,000
• CF4 = 35,000
• CF5 = 40,000 + (40,000/0.1)

1. IRR = ?
2. I (InvestRate=financeRate) = 7 %, RI (ReInvestRate) = 4 %, MIRR = ?

※ irr()만 있고, mirr() 기능이 없는 계산기에서의 계산 방법

1. 매기 현금흐름 중에서
   【+ 현금흐름】은 재투자율로 미래가치로 계산, 
   
   └ nspire에는 nfv() 함수가 없으므로 npv()  tvmfv() 2단계 거침.

   【- 현금흐름】은 (내부수익률이 아닌!) 시장이자율로 현재가치로 계산
    

2. 【초기투자액】 +  【- 현금흐름】 현가 = 【+현금흐름】 재투자후 미래가치의 현가
   를 만족하는 irr 값을 찾으면 그것이 MIRR