You join a company that has just opened an online store in Portugal. Demand is low and your task is to find out why that might be the case. Your manager suspects that online buyers do not trust the Portuguese as much as hey would trust individuals from Western Europe, such as the Netherlands. In order to assess this belief, Table D shows some variables that your manager has collected for a random sample of 15 European countries during b. The R-square for the above linear regression equation is 0.68. What information does this number give 2010-2013 (n = 4 years * 15 countries = 60), while Figure 1 shows a scatter plot of Ecommerce sales versus us about the association between Trust and Ecommerce sales? Trust. (5 marks) Table D: Variables and descriptive statistics c. Calculate the 95% confidence interval for Ecommerce sales. What does this confidence interval tell us Variable Description Mear SD Min Max about Ecommerce sales in the population of European countries? 5 marks) Trust The level of trust in individuals in country i 0.87 16.62 -27.6 23 Ecommerce sales % of Companies in country i that made online sales 20.40 7.7 38 You believe that a regression model of Ecommerce sales as a function of Trust must also account for differences in the size of country's economies (i.e., GDP) as well as calendar years. Table E shows the relevant multiple linear regression model. GDP Logarithm of total GDP (in MME) of country i 13.13 0.96 11.97 14.82 Table E: Multiple regression of Ecommerce sales versus Trust, GDP, and Calendar years Year_2011 Dummy variable; 1 if year = 2011, 0 if year ? 2011 0.25 0.44 Dependent variable Ecommerce sales Year_2012 Dummy variable; 1 if year = 2012, 0 if year ? 2012 0.25 0.44 adjusted R-squared 0.66 Year_2013 Dummy variable; 1 if year = 2013, 0 if year ? 2013 0.25 0.44 F-test (p-value of F-test) 24.39 (0.000) Coefficient Standard error Figure 1: Scatter plot of Ecommerce sales versus Trust (2010-2013) Trust 0.38 0.04 40 GDP -1.037 0.61 Year_2011 -0.435 1.63 35 Year_2012 -0.220 1.63 30 Year_2013 -0.816 1.63 25 Constant 34.06 8.12 20 d. Based on the information in Table E, interpret the association between Trust and Ecommerce sales in Ecommerce sales (%) this estimated regression equation. Use a 95% confidence interval. (5 marks) 15 ... e. Assuming a = 0.05, do ecommerce sales in 2011, 2012, or 2013 differ significantly from those in 2010? 10 5 marks) .30 -20 -10 10 20 30 Trust The simple linear regression line that best fits the data points in the scatter plot in Figure 1 is as follows: (1) Ecommerce sales = 20.06 + 0.39 * Trust a. Based on this estimated linear regression equation, what would be the predicted level of ecommerce sales for Portugal, assuming Trust in Portuguese citizens is equal to -18.4? And what would be the predicted level of ecommerce sales for the Netherlands, assuming Trust in Dutch citizens is equal to 19.1