Question

American customer satisfaction index: Starbucks in the U.S. 2006-2016

2006	77
2007	78
2008	77
2009	76
2010	78
2011	80
2012	76
2013	80
2014	76
2015	74
2016	75

This statistic shows the American customer satisfaction index scores of Starbucks in the United States from 2006 to 2016. Starbucks had an ACSI score of 75 in 2016. Just over 50 percent (around 7,880) of all Starbucks stores were company-operated stores, from which Starbucks generates around 79 percent of its revenue. Around 5,292 stores are licensed stores. Starbucks, which became a publicly traded company on June 26, 1992, generated around 21.32 billion U.S. dollars in revenue in the 2016 fiscal year. In its company-operated stores Starbucks generates 74 percent of revenue from the sale of beverages, 19 percent from food sales and three percent from the sale of packaged and single serve coffees. Another four percent of retail sales are attributable to coffee-making equipment and other merchandise. The United States is Starbucks’ biggest and most important market. In 2016, revenues from Starbucks Americas segment amounted to more than 14 billion U.S. dollars. The Americas segment comprises over 13,000 stores in the U.S., Canada, Mexico, Puerto Rico, Brazil Chile and other American countries with around 86 percent of those stores located in the United States. 1. Plot this set of data as a scatterplot in excel. 2. Find the correlation coefficient. 3. Is it positive or negative? 4. What does the sign tell us? 5. What does the correlation imply about the relationship between the time and the satisfaction? 6. Is the correlation significant? Why or why not? (Answer in 1-2 complete sentences.) (Use the Pearson calculator). 7. Draw the trendline in excel. Can the regression line be used for prediction? No, it is too weak. Insert excel graph here:

Answer 1

1. Plot this set of data as a scatterplot in excel.

2. Find the correlation coefficient.

r = 0.366

3. Is it positive or negative?

Positive

4. What does the sign tell us?

There is a moderate relationship

5. What does the correlation imply about the relationship between the time and the satisfaction?

There is a moderate positive relationship between the time and the satisfaction.

6. Is the correlation significant? Why or why not? (Answer in 1-2 complete sentences.) (Use the Pearson calculator).

The critical value is 0.602.

Since 0.366 < 0.602, we fail to reject the null hypothesis and we can conclude that the correlation is not significant.

7. Draw the trendline in excel. Can the regression line be used for prediction? No, it is too weak. Insert excel graph here:

No, the regression line cannot be used for prediction.