What is the relationship between diamond price and carat size? 307 diamonds were sampled and a straight-line relationship was hypothesized between y = diamond price (in dollars) and x = size of the diamond (in carats). The simple linear regression for the analysis is shown below:

Least Squares Linear Regression of PRICE

Predictor
Variables Coefficient Std Error TP
Constant -2298.36 158.531 -14.50 0.0000
Size 11598.9 230.111 50.41 0.0000

R-Squared 0.8925 Resid. Mean Square (MSE) 1248950
Adjusted R-Squared 0.8922 Standard Deviation 1117.56

Interpret the estimated slope of the regression line.