How to compare a constant variable against independent variable.?

I have constant variables such as male, female, non smoker and smoker.

how do compare each of these grouped factors with a independent variable abdominal diameter cm.

I have calculated mean, sd and range but how to I calculate there significance.How to compare a constant variable against independent variable.?
How can something be "constant" and "variable" at the same time?



Maybe what you have are independent and dependent variable. The abdominal diameter depends on whether the subject is male/female, smoker/nonsmoker. So the diameter is the dependent variable, and the sex (or smoking) is the independent variable.



Testing for significance is tricky; you can read about it in books and on the web.How to compare a constant variable against independent variable.?
A ven diagram should help show significance

natural makeup