I know, I sound stupid, but I'm French and I can't think of a way to say it. Here's the example I have:
In 2008 there were $44$ million pager subscribers. By 2014 the number of subscribers increased to $64$ million. What is the geometric mean annual increase for the period?
Apparently the answer is $6.44%$, so $\frac{64}{44}-1$, and then square root with the variable $6$ before it; I can't figure out how to put this into the calculator and get the same result.
The following is called the sixth root of $\frac{64}{44}$: $$\sqrt[6]{\frac{64}{44}}=\left(\frac{64}{44}\right)^{1/6}$$