Find the effective rate of an account that earns 5 compound
Find the effective rate of an account that earns 5 % compounded:
 Round your answer to the nearest hundredth of a percent.
 
 semi-annually:
 
 quarterly:
 
 monthly:
 
 daily:
 
 continuously:
Solution
Let us suppose the principle ammount is X. Now if 5% compounded semi annually then interest rate per 6 months
i = 5% / 6
= 0.83%, Number of interest period per year is 2
So for a year at 5% compounded semiannually the ammount of interest you earn is:-
ia = effective annual interest rate per year.
r = Nominal interest rate per year
M = Number of interest period per year
So we have ia = (1 + r/M)M - 1
Put the values ia = (1 + 5/2*100)2 - 1 = (1+0.025)2 - 1 = (1.025)2 - 1 = 1.050625 - 1 = 0.050625 = 5.06% compounded halfyearly
Now if compounde quarterly the M = 4 then the formulae becomes
ia = (1 + 5/2*100)4 - 1 = (1+0.025)4 - 1 = (1.025)4 - 1 = 1.103812890625 - 1 = 0.103812890625 = 10.38% compounded quarterly
Now if compounde monthly the M = 12 then the formulae becomes
ia = (1 + 5/2*100)12 - 1 = (1+0.025)12 - 1 = (1.025)12 - 1 = 1.3448888242462984371781349182129 - 1
= 0.34488882424629843717813491821289 = 34.48% compounded monthly
Now if compounde daily the M = 365 then the formulae becomes
ia = (1 + 5/2*100)365 - 1 = (1+0.025)365 - 1 = (1.025)365 - 1 = 8206.499557696606902207435986129 = 820649.95% compounded daily

