https://towardsdatascience.com/calculating-price-elasticity-of-demand-statistical-modeling-with-python-6adb2fa7824d?_branch_match_id=694097693223397494&&gi=803b77fb0f3a
https://towardsdatascience.com/calculating-price-elasticity-of-demand-statistical-modeling-with-python-6adb2fa7824d?_branch_match_id=694097693223397494&&gi=803b77fb0f3a