Has the number of home runs hit by major league teams been increasing over time? For the 41 years from 1960 to 2000, the average number of home runs hit per game per team was computed in order to assess any change over time. Initially, a simple linear regression was used to study the trend in the average number of home runs over the period 1960 to 2000 by using year to predict average number of home runs per game per team in that year. However, it was pointed out that after the 1976 season the manufacturer of major league baseballs was changed from Spaulding to Rawlings. Because the change in the baseball used might affect the number of home runs (for example, if Rawlings produces a livelier ball, this would likely lead to more home runs), it was decided to include an additional variable, namely manufacture = {0 if before 1976 (that is, the Spaulding baseball was used), and 1 if after 1976 (that is, the Rawlings baseball was used). A multiple linear regression analysis was performed using the model: Avg. home runs per game per team = B0 + B1(Year) + B2(Manufacturer). The following results were obtained:

Analysis of Variance

Source df Sum of Squares

Model 2 0.744384

Error 38 2.539330

Parameters Estimates

Variable df Parameter Estimate Standard Error

Intercept 1 -27.91180 12.8900

Year 1 0.014977 0.00650

Manufacturer 1 -0.107816 0.11573

The value of the regression standard error is: 0.259.

I don't understand how to get the value of the regression standard error.