acutal data the last six quarters of business is shown below:

Q3 21= 8, Q4 21 = 9, Q22 = 12, Q2 22 =14 , Q3 22= 16, Q4 22 = 26

Calculate a four- period weighted average demand forecast for Q1 23. Use 50% weight for the most recent period , 25 % for the period before that, 15 % for the period before that and 10 % for the period before that. Show your work: round to one decimal.