A retail store estimates that weekly sales s and weekly advertising costs x (both in dollars) are related by s =70,000 - 30,000e 0.00025x. The current weekly advertising costs are $4,000, and these costs are increasing at a rate of $400 per week. Find the current rate of change of sales. The current rate of change of sales is $ per week. (Round to the nearest dollar as needed.) 1, of an example Get more help - Clear all Check