A department store has purchased 4000 items to be sold during the summer sales season. The season lasts three months and the store manager forecasts that customers buying early in the season are likely to be less price sensitive compared to the customers buying later in the season. The demand curves in each of the three months are forecast to be as follows: d1=2000-15*p1, d2=2000-25*p2 and d3=2000-40*p3. If the department store wants dynamic prices that vary each month, (i) what should they be? (ii) Provide your comments on the price sensitivity of the customers as captured in the model? (iii) Justify the purchase of 4000 units at the start of the season. (iv) What is the total profit earned if the purchase price of each item is $30.0?