Data collected from supermarket checkout counters can be used to evaluate the effect of price on the sales of any product. Weekly data was collected on a particular beverage brand, including sales (y, in number of units) and price (r, in dollars) from 8 stores. In the sample data, r has a sample mean of 20 and a sample standard deviation of 2, while y has a sample mean of and a sample standard deviation of 9 The sample correlation between r and y is -0.8. Required:
Compute the simple linear regression equation