Brewsky's is a chain of micro-breweries. Managers are interested in the costs of the stores and believe that the costs can be explained in large part by the number of customers patronizing the stores. Monthly data regarding customer visits and costs for the preceding year for one of the stores have been entered into the regression analysis and the analysis is as follows: 1.462 $4,629 Average monthly customer-visits Average monthly total costs Regression Results Intercept b coefficient R2 $1.496 $2.08 0.86814 In a regression equation expressed as y = a + bx, how is the letter b best described? The fixed costs per customer visit The estimate of the cost for an additional customer visit An estimate of the probability of return customers. The proximity of the data points to the regression line