Question: The income ( \({{Y}_{i}}\) in $100 000) and number of patients (x in 100s) is recorded in n = 10 medical practices, yielding data for which the summary statistics are

Obtain \({{C}_{XX}}\), \({{C}_{YY}}\) and \({{C}_{XY}}\), and show that the fitted regression line of Y on X has slope a = 0.0867 and intercept b = 0.6091, and calculate the estimate s of the standard deviation σ for the model.