CONSIDER THE FOLLOWING ESTIMATED AR(2) MODEL TO ANALYZE THE QUARTERLY SALES:

ASalest = 10 + 0.55 ASalest-1 +0.25 ASalest-2 The last quarter in the data is the fourth quarter of year 2020. The Sales for the periods 2019.3 through 2020.4 are listed in the following table: Period 2020.4 2020.3 2020.2 2020.1 2019.4 2019.3 Sales $2,000 $1,800 $1,500 $1,400 $1,900 $1,700 Question A: Use the time series model above to forecast the sales for the second quarter of year 2021 (i.e. 2021.2)? Question B: After the analyst used the AR(2) to analyze the change of sales in question (A) over time, he wanted to examine if the changes of sales have heteroskadasticity. Which model should be used to examine the Autoregressive Conditional Heteroskadasticity? Write down the model and the procedure on how to examine the ARCH effect of change of sales. Question C: The Ljung-Box test for the residuals has the p-value of 18% in AR(2), determine if residuals are white noise or not given 5% of significance level