A company manufactures and sells DVD's. Here are the equations they use in connection with their business. 

Number of DVD's sold each day: \( n ( x ) = x \) 

Selling price for each DVD: \( p ( x ) = 11.5 - 0.02 x \) 

Daily fixed costs: \( f ( x ) = 160 \) 

Daily variable costs: \( v ( x ) = 2 x \) 

Find the following functions.

a. Revenue \( = R ( x ) = \) the product of the number of DVD's sold each day and the selling price of each DVD.

 \( R ( x ) = \square \) 

b. Cost \( = C ( x ) = \) the sum of the fixed costs and the variable costs. 

\( C ( x ) = \square \) 

c. Profit \( = P ( x ) = \) the difference between revenue and cost. 

\( P ( x ) = \square \) 

\(d \) . Average cost \( = \overline { C } ( x ) = \) the quotient of cost and the number of DVD's sold each day. 

\( \overline { C } ( x ) = \square \)