A question regarding the calculation of the annual average growth rate in CAPEX spending:
The author takes the 2009 CAPEX amount, $197 (in millions), and divides by $180 (the 2006 CAPEX), to obtain 1.094. Then take the log of that, divide by the number of years growth rate (in this case 3, i.e. 2006-2009), and then take the antilog of that for an average growth rate of 3.1% per year. Now why is it necessary to take the log and the antilog to derive an accurate estimate of the average annual growth rate in CAPEX over the desired period? Thats my main concern, is why is the logarithms?

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