How would I use a logarithmic model (y = a + b ln x) for the information that is in the picture? X is the number of jackets so the 1000, 2000 3000 and so on and the Y can be either the price demand or the price supply.

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.