Statistics for Business: Decision Making and Analysis, 3rd Edition

... estimate, its standard error, and the derived t-statistic and p-value.

Table 23.4 Estimated coefficients from the multiple regression of sales on income and competitors.

Term		Estimate	Std Error	t-Statistic	p-Value
Intercept	b0	60.3587	49.2902	1.22	0.2254
Income	b1	7.9660	0.8383	9.50	< .0001
Competitors	b2	− 24.1650	6.3899	− 3.78	0.0004

The procedure for building confidence intervals for these estimates is the same as in simple regression. The only difference is an adjustment to the degrees of freedom that determine the t-percentile. For a regression with k explanatory variables, the 95% confidence intervals for the coefficients have the form

$$\text{estimate}\pm t_{0.025\text{, }n-k-1}\text{se}\left(\text{estimate}\right)$$

In this example, n = 65 and k = 2, leaving n − k − 1 = ...