Hi all,

Having trouble calculating interest for an assignment

Basically I need to work out what an annual interest rate of 4.5% would be when adding it to total sales for a week (interest has to be added to the total sales at the end of the week, based on a 6 day selling week)

and how would an annual rate of 4.4% be applied at the end of each day when ading to total sales

Is this compound interest?

sorry its a bit early to be asking these questions but any help would be much appreciated!

 

Yeah thats just basic compound interest by the sounds of it mate.

To turn the anualised rate into a daily one you just divide it by 365 (fook leap years, lol)

Then to compound it over a number of days you simply do X * (1 + dailyinterest)^NumberDays

 

ah right, so to calculate a weeks interest is:

(4.5% / 365 days)^5

Thanks for your help

 

its 1 + (0.045/365)^7

 

ooh ok thanks for that mate.

and the daily one is just 1 + (0.045/365)

 

Yeah thats right mate.

Just hope they dont get you doing aus yields and shit, thats when it starts getting complicated, lol

 

lol this is for a mates assignment, vaugely remember doing it just couldnt remember so thanks for all your help

 

OK this is doing my head in

can some one please help me out

basically I have two interests to work out, weekly and daily

The sales total is £81,588 for an 18 week period, based on 6 day selling weeks thats 108 days

The daily interest rate is 4.4%
The weekly interest rate is 4.5%

When I work out the two interests I get a difference of about 20p!!!!

If anyone can explain or show me the right way to do it that would be great as I am running out of time