hello i am stuck on this question. for some reason i ened up with 6.69

A stock originally purchased exactly 3 years ago for $11.37 per share is currently vaiued at $20.37 per share - what is the Geometric Mean Return generated by this investment since its original purchase date (assume annual compounding)? (2) 79.16% 14.73% 17.66% 21.45% 21.14% 26.39% 19.29%