write a c program that calculates the Max , Min , Average and Variance of 10 numbers enterd by user and stored in array

OK, I have written it. Have you? You can buy my version for only 99USD and pretend its yours if you want. Then you will pass your course and everyone will know how clever you are.

Now go back and read DaniWeb's rules , especially "Do provide evidence of having done some work yourself if posting questions from school or work assignments"

The OP might want to also consider that C and C# are not the same language, and that C++, Objective C, and Objective C++ are yet other different languages from those and each other, as well. Any answer we give will greatly depend on knowing what language the assignment is meant to be in. While it should be evident from the code in most cases, you haven't posted any, so we are left in the dark about it.

I am guessing that the language in question is actually C (which is hat the assignment description reads), not C# (as per the thread title and tags) or any of those others, but that is because I am assuming that you simply pasted the assignment into the post without changing it.