I want to test whether the coefficient of Var 3 significantly is different from zero at significance level of pvalue of 0.01 , or if it not (so equal to 0). If it is different from zero, i would like to know whether the coefficient is then > 0 or < 0.
Moreover, i want to test whether also whether the coefficient of Var5 bigger or smaller than the coefficient of Var4 at a level of 0.01, or whether the coefficient of Var5 does not differ significantly from the coefficient from Var4 (so Var5 = Var4 at significance level of P value < 0.01).
Any help would be highly appreciated. I am still new to R so i do not understand this completely.
The first question is easy. You want a "one-tailed" test rather than a "two-tailed" test. For example, if you want the one-tailed critical value at the 5 percent level with 95 degrees of freedom use qt(0.05,1000).
To test hypotheses involving multiple coefficients take a look at linearhypothesis in the car package. Some guidance is given at Linear Hypothesis Tests | LOST
What part of the plot represents the coefficient? What part represents a coefficient of zero? Is there a difference? What would cause someone to doubt that the difference was not simply the result of random variation?