GoodMorning is a new line of probiotic juice products. Since its first product launch in 2015, GoodMorning were now on the shelves of nationwide retailers. GoodMorning had the challenge of raising product awareness, particularly about the benefit of probiotics and the great taste. As a recent stat-up in the fairly new probiotic market, GoodMorning did not have the funding to place nationwide advertisements. It instead allocated much of its small marketing budget to in-store demonstrations.

During in-store demonstration, GoodMorning representatives handed our product samples. The representative arrived at a specified store, set up a table, distributed samples, informed consumers about the product, and offered coupons to inspire purchase.

Another promotional program involved competitions among the five GoodMorning sales representatives for the most endcap displays. The endcap is the hub at the end of an aisle-one of the store's most popular locations. Sales representatives competed for the highest number of stores they could convince to place GoodMorning's products at the endcap. The winning sales representative received a big screen television. There was also a competition for the best-decorated endcap. The winning store received cases of product for the employees and gift cards.

The company's in-store demo was launched in November of 2016. Due to limited marketing resources, management was pressured to cut any marketing expense that did not directly contribute to GoodMorning's results. By July of 2017, several concerns were raised within the company about the effectiveness of the in-store demo program. Some questioned whether the demos boosted sales at all, while others were concerned that any boost was only temporary and that sales would revert to normal levels shortly afterward. Some executives questioned whether the increase in sales volume could justify the associated costs.

At the senior manager meeting, GoodMorning management asked Jim Martin, GoodMorning's Marketing manager to justify the demo and endcap activities. Jim returned to his computer after the meeting and pored over the sales and promotion spreadsheet from the last few months. He recognized that statistics could be used to help his case. He decided to apply regression analysis to the sales and promotion data (GoodMorning.xlsx) to enable a decision on whether or not the company should continue its promotional programs.

Model A:

Build a regression model with all variables in the data to explain the relationship between sales and promotional efforts. Let us refer to this model as ModelA. Create the residual plot and the scatter plot of fit vs. UnitsSold.

a) Copy and paste the R code, the regression output, and the plots.

b) Discuss the performance and validity of the model, and how to improve and refine the model.

https://docs.google.com/file/d/1xUMSkY0loffe7B_rtjyu7D12LWtWOS2e/edit?usp=docslist_api&filetype=msexcel