I need to see all answers in Excel and complete question $3.$

Using Excel to complete the following questions. You may give your answers to all of the

questions in the Excel file and upload the Excel file only to Blackboard. If so$,$ you must indicate

your answers clearly. Alternatively, you may give your answers in the Word file and upload both

the Word and Excel files to Blackboard.

$(35$ Points$)$ Sales data for two years are as follows. Data are aggregated with two months of

sales $($in $1,000$ units$)$ in each "period."

a$)(5$ Points$)$ Plot the data.

b$)(12$ Points$)$ Fit a linear regression model to all the sales data.

c$)(12$ Points$)$ In addition to the regression model, determine multiplicative seasonal index

factors. A full cycle is assumed to be a full year.

d$)(6$ Points$)$ Using the results from parts b$)$ and c$),$ prepare a forecast for the next year.

$(35$ Points$)$ Zeus Computer Chips Inc. used to have major contracts to produce the Centrino$-$

type chips. Here is demand over the past $12$ quarters:

Fit a linear regression model with an additive form $($using dummy variables$)$ to forecast the

four quarters of $2024.$

$(30$ Points$)$ The demand manager of Maverick Jeans is responsible for ensuring sufficient

warehouse space for the finished jeans that come from the production plants. In order to

estimate the space requirements, the demand manager is evaluating moving$-$average

forecasts. The demand $($in $1,000$ case units$)$ for the last fiscal year is shown below.

a$)(13$ Points$)$ Use a three$-$month moving average to estimate demand forecasts for

months $4-12$ and generate a forecast for the first month of next year. Calculate mean

absolute deviation $($MAD$)$ for months $4-12.$

b$)(13$ Points$)$ Use an exponential smoothing method with a starting forecast of $25$ for

month $1$ and a smoothing constant $=0\mathrm{.}4$ to calculate demand forecasts for months $4-$

$12$ and forecast for the first month of next year. Calculate the MAD for months $4-12.$

c$)(4$ Points$)$ Compare the MAD for the forecasting methods in parts a$)$ and b$).$ Based on

these error calculations, which of the two forecast methods would you recommend?