The Honey Comb Project

I am currently practicing the honey comb project.
https://www.codecademy.com/paths/finance-python/tracks/regression-for-finance/modules/linear-regression-python-finance/projects/honey-production
at step three i keep getting this error:
AttributeError: Cannot access attribute ‘values’ of ‘SeriesGroupBy’ objects, try using the ‘apply’ method

Thank you !