Need help solving C the correct answer is there but I got it wrong, Please and thank you (I cant seem to get the formula correct for C)

The Bonavista Patient Transfer Company is considering the purchase of a new ambulance. The decision will rest partly on the anticipated distance to be driven next year. The kilometres driven during the past 5 years are as follows:

Year 1 2 3 4 5 Distance 3,100 4,000 3,450 3,800 3,700

a) Using a 2-year moving average, the forecast for year 6 is 3750 kilometres (round your response to the nearest whole number).

b) If a 2-year moving average is used to make the forecast, the MAD based on this is 83.3 kilometres (round your response to one decimal place). (Hint: You will have only 3 years of matched data.)

c) The forecast for year 6 using a weighted 2-year moving average with weights of and (the weight of is for the most recent year) is 3,735 kilometres (round your response to the nearest whole number).

The MAD for the forecast was developed using a weighted 2-year moving average with weights of and = enter your response here kilometres (round your response to one decimal place). (Hint: You will have only 3 years of matched data.)