$2.$ For the following dataset $($Port entry into Detroit$),$ construct the multiplicative seasonal model and predict the monthly truck flow for the year $2020($All $12$ months$)-9$ points

i$)$ We need the seasonal indices

ii$)$ We need the final forecasting model using the decomposition technique

iii$)$ We need the forecast for the next twelve months using the winters multiplicative model

iv$)$ What is the WMAPE for the model?