Sales of Volkswagen's popular Beetle have grown steadily at auto dealerships in Nevada during the past 5 years (see table below).

Year Sales 1 450 2 502 3 520 4 555 5 585

a) Forecasted sales for year 6 using the trend projection (linear regression) method are 619.3 sales (round your response to one decimal place).

b) The MAD for a linear regression forecast is 4.88 sales (round your response to one decimal place).

c) The MSE for the linear regression forecast is sales (round your response to one decimal place). explain how you got it