The following example is related to the application of integral calculus in business. Explain in details what is the rate of growth or sale. Next, using your own creativity, present the solution to the following problem. The rate of change of sales of a company after an advertisement campaign is represented as f(t) = 30003'0'3t, Where t represents the number of months after the advertisement. Find out the total cumulative sales after 4 months and the sales during the fth month. Finally, find out the total sales due to the advertisement campaign