Suppose that after reading Hal Varian's paper on "How to build an economic model in your spare time" you decided to build a regression model to explain the number of customers (Customers) at a cross section of 202 different Beacon Hill Restaurants as a function of the number of nearby competitors (Competitors). Using Stata, you conducted a simple regression analysis and your estimated model is given by Customers; = 100,000-9,000 Competitors + ej, (20,000.0) (3,000.0) where Customers is measured as the continuous number of customers per year (in 100s customers) and Competitors is measured as the continuous number of the similar restaurants nearby per year. You have reported the standard errors of the coefficient estimates in parentheses. Also, you have computed that R2 = 0.50, SER = 100. Multiple Choice - Select one correct answer. Using the information about R2 and SER, find the sample standard deviation (sy = sy) of the dependent variable (the number of customers) across 202 observations. Choose one correct answer. O A. 121 OB. 156 O C. 136 O D. 141