[R] Std. errors of intercept and slope

[Yao, Minghua]

Dear all,

I have the following output generated by linear regression. Since there is
only one regression intercept and one slope for one set of data, what is the

meaning of std. error for intercept and that of slope? Thanks in advance.

Sincerely,

Minghua


> data(thuesen)
> attach(thuesen)
> lm(short.velocity~blood.glucose)

Call:
lm(formula = short.velocity ~ blood.glucose)

Coefficients:
  (Intercept)  blood.glucose  
      1.09781        0.02196  

> summary(lm(short.velocity~blood.glucose))

Call:
lm(formula = short.velocity ~ blood.glucose)

Residuals:
     Min       1Q   Median       3Q      Max 
-0.40141 -0.14760 -0.02202  0.03001  0.43490 

Coefficients:
              Estimate Std. Error t value Pr(>|t|)    
(Intercept)    1.09781    0.11748   9.345 6.26e-09 ***
blood.glucose  0.02196    0.01045   2.101   0.0479 *  
---
Signif. codes:  0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1 

Residual standard error: 0.2167 on 21 degrees of freedom
Multiple R-Squared: 0.1737,     Adjusted R-squared: 0.1343 
F-statistic: 4.414 on 1 and 21 DF,  p-value: 0.0479 

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