Final answer:
To calculate the yearly average seasonalized forecast demand for 2023, use the given model ŷ = 101.32 + 2.48x, where ŷ represents the sales in thousands of dollars and x represents the day. Substitute the corresponding day values for each month into the model to predict the sales.
Step-by-step explanation:
To calculate the yearly average seasonalized forecast demand for 2023, you need to use the given model ŷ = 101.32 + 2.48x, where ŷ represents the sales in thousands of dollars and x represents the day.
Since the question asks for the monthly average, you need to find the average sales for each month in 2023. To find the sales for a specific day in January, February, or March of 2023, you will substitute the corresponding days (1-31, 32-59, 60-90) into the model.
For example, to find the sales on day 60, you substitute x = 60 into the model: ŷ = 101.32 + 2.48 * 60.
Calculate the predicted sales for each month in the same way, and then find the average for each month to get the monthly average seasonalized forecast demand.