Urgent how to calculate the Fair price of the future

[bettyhan]

In 31 July
If the Spot sterling interest rate (3-mo)= 8%
Spot FTSE 100 index =2000
Dividend yield on the FTSE100 =5%

how to calculate the fair price of the FTSE100 contract if its delivery date for contract is in 30 October???

i know the equation
@fair price=spot index+(interest rate-dividend yield)Xspot index@

but one problem is the interest rate in equation is denoted as annual interest rate or the term interest rate???
8%= interest rate or 8%*90/365????????

please help !!
thanks
i am so confused

 

[Capricorn]

Int rate should be on the term of the futures contract.