Beverage companies advertising effectiveness compared

Revenue Growth: R_t=bP_{t-1}+e

Where R_t is revenue growth as a function of time, P_{t-1} is the percent of revenue spent on advertising in the time period (quarter or year), and e is accounting for any extraneous circumstances throughout the time period i.e. pandemic.

Goal: find the relationship between beverage company advertising as a percent of revenue and the percent revenue increase in the next quarter/year