Part A$.$ A brand manager is examining some data that shows advertising

budgets for various months and sales. She is interested in knowing if advertising

dollars can be used as a predictor of sales. Here are some data for a particular

region $($all data are hundreds of thousands$)$:

Month

Advertising

Expenditure

Actual Sales

February $512$

March $513$

April $615$

May $711$

June $511$

July $714$

August $717$

September $516$

October $820$

a$.$ Using simple linear regression analysis, calculate the regression equation for

this set of demand data.

b$.$ If the brand manager is budgeting $$750,000$ for November, what is the

predicted sales?

c$.$ Does the trend line represent a good fit to the data? Please provide the

appropriate statistical evidence