Exercisen$1$

In$-$Class Lab & Homework Assignments

Below are car sales by time $($dependent varlable$)$ by time $($Independent varlable$)$:

$\backslash$table$[[$Month$,\backslash$table$[[$Automotive$],[$Sales Data$]]],[$Jan$-23,21\mathrm{.}2],[$Feb$-23,21],[$Mar$-23,20\mathrm{.}5],[$Apr$-23,20],[$Mar$-23,19\mathrm{.}8],[$Jun$-23,19\mathrm{.}6],[$Jul$-23,17\mathrm{.}6],[$Aus$-23,16],[$Sep$-23,15\mathrm{.}2],[$Oct$-23,14],[$Nov$-23,13],[$Dec$-23,127],[,]]$

For the automotive sales dataset, generate a line chart Illustrating the relationship between sales and time, To facilitate this, include a third column titled "Time index" and populate it beginning with the number $"1"$ and increment by $1$ for each subsequent row,

Write out the general simple linear trend equation for this example where auto sales is the dependent variable and thine is the independent variable.

Start with:

Auto Sales $=$

Determine the Intercept $(b_s)$ and slope $(b_y)$ for this data $($see the end of this document for Instructions on how to find these coefficients using Excel$).$

Plug the intercept and slope numbers Into the general simple linear trend equations from step $2$ and write out the regression forecast model

Evaluate the sign of the slope value within your simple linear trend regression model. Provide a sentence describing your evaluation.

Start with:

The sign $-$

Exercise #$2$

From assignment #$1$ results, write out $($in text$)$ the formulas to calculate the trend estimates for Feb$-23,$ Jul$-23,$ and Dec$-23$

For example, start with:

Feb$-23$ Forecast $=$

Create a table to organize your data and calculate forecasts for Jan$-23$ through Jan$-24($follow the formatting guidelines discussed in class and documented in the Chapter $1$ exercise instructions; all calculations must be imbedded in the cells within the table$)$

Calculate the MAPE for this forecast $($include only Jan$-23$ through Dec$-23$ in calculations$)$

Create a line graph that includes the following two data series$*$:

Actual automotive sales data

Forecast automotive sales data

What is the forecast for Jan$-2025?($You may add this as a row in your table from step two$)$

What is the forecast for Jan$-2026?($You may add this as a row in your table from step two$)$