1. My dependent variable is continuous (Number of years)

2. I have 8 independent variables, 1 is continuous (number of vehicles passing through the bridge) and remaining are categorical (Type of the bridge, Type of edge beam, Material of the beam, Structural type of the beam, Climate zone, Road type, Road category)

3. Each categorical data have more than 6 subcategory (Type of bridge has 22 category, Type of beam-15, material of the beam-7, Structural type-10, Climate zone-6 etc)

4. How I can find which category data has no much effect on my dependent variable? Is it by Anova? If I am getting significance level less that 0.05 in anova test, does it mean that, that categorical data have an effect on my dependent variable?

5. How can I find the regression equation? My aim is to find a linear equation like N=Ax+By+Cz... etc, where A,B,C are coefficients and x,y,z are the inputs for above mentioned continuous and categorical variable. I have created dummy variables for each categorical data. ie, 21 dummy variables for bridge type, 14 for type of beam etc. Now how I will do the regression test by including both the continuous variable and 7 categorical data?

6. Once I get the regression coefficients, how can I create the regression equation from it, as we are using only k-1 dummy variables and we will get k-1 coefficients and a constant. So what is the coefficient for the 'k' th category?

If I asked anything stupid, pls excuse me. I started learning statistics only one week before and I have no basic idea of this subject

It is urgent

Thanks in advance!!

Regards

Sobhit