The fets() function below returns ETS forecasts. a. Apply tsCV() for a forecast horizon of h = 4, for both ETS and seasonal naïve methods to the qcement data, (Hint: use the newly created fets() and...

The fets() function below returns ETS forecasts.

a. Apply tsCV() for a forecast horizon of h = 4, for both ETS and seasonal naïve methods to the qcement data, (Hint: use the newly created fets() and the existing snaive() functions as your forecast function arguments.)

b. Compute the MSE of the resulting 4-step-ahead errors. (Hint: make sure you remove missing values.) Why are there missing values? Comment on which forecasts are more accurate. Is this what you expected?