The given problem lacks the data about the price of the single product. However assuming that the selling price is similarly $44 which I got from other references, then we can now calculate for the net change of the monthly operating income.
So to solve for the change, we use the formula:
Change in net operating income = Increase in units * Selling price – Increase in advertising budget
Change in net operating income = 170* $44 – $6,000
Change in net operating income = $1,480
Since the change is positive, then it is a good decision to increase the monthly advertising budget by $6,000.