Is this formula correct?

[웃 910]

I Just divided the first column by the second column and multiplied by 100....Asking here because someone on the internetz said a more accurate way was to do this:

real rate = (1 + nominal rate) / (1 + inflation rate) - 1 whereas inflation rate is equal to (current cpi / previous cpi) - 1

I like my formula better, but is it incorrect???

Thanks for any input, the class is intermediate economics, in case anyone was wondering.

[Ban Hammer 14,098]

the gecko will know.