The following two investment options are viewed under an annual effective interest rate of i.

Investment A is a 10-year zero coupon bond which redeems at par-value 250.

Investment B is a perpetuity-immediate paying an annual payment starting with 4 and having each successive payment increase by X% from the previous payment. If the volatility of each investment is 8, then find the value of X.

Give your answer as a percentage rounded to two decimal places.