Over the years the U.S. grocery distribution and sales industry has grown. Today, the total industry sales are in the billions of dollars. Major retailers, such as Walmart and Target, added food to complement their merchandise sales and Amazon recently purchased Whole Foods. For many companies, forecasts of industry sales are necessary information to plan for short- and long-term decisions. Using the total U.S. grocery store annual sales in millions of dollars (https://www.census .gov/retail/index.html#mrts) in the following table, respond to the following items.

a. Graph the data.

b. Based on the graph, describe the time series pattern.

c. For this time series, why is forecasting with a trend model appropriate?

d. Evaluate a trend forecasting model using simple linear regression. What is the MAD?

e. What is the predicted annual change of industry sales?

f. Using the trend model, forecast the next 3 years of grocery sales.

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Year Sales Year Sales 2008 $511,222 2013 $574,547 2009 510,033 2014 599,603 2010 520,750 2015 613,159 625,295 639,161 2011 547,476 563,645 2016 2012 2017