So, in order to calculate x, you have to be able to find the fourth root of (Year5/Year1). The formula to find the fourth root is to raise the number to the 1/4 power. Thus, the formula to calculate the compounded growth rate is: (Year5/Year1)^(1/4)-100% = x.
To prove that this formula is working, multiply year 1 by 1.5884235 four times. The answer should be very close to Year 5.
Figure 370 Compounded growth rate.
Figure 371 Prove that the 58.84% growth rate is accurate.