We want to apply the Holt-Winter method, assuming a cycle of one year and a quarterly time bucket, corresponding to ordinary seasons. We are at the beginning of summer and the current parameter estimates are

• Level 80

• Trend 10

• Seasonality factors: winter 0.8, spring 0.9, summer 1.1, autumn 1.2 On the basis of these estimates, what is your forecast for next summer? If the demand scenario (summer 88, autumn 121, winter 110) is realized, what are MAD and MAD%?