High$-$low method

The manufacturing costs of Schroeder Industries for the first three months of the year follow:

$\backslash$table$[[,$Total Costs,Units Produced$],[$January$,$$$243,000,1,215$ units$],[$February$,322,920,2,310,..],[$March$,378,000,3,915]]$

Using the high$-$low method, determine $($a$)$ the variable cost per unit and $($b$)$ the total fixed cost.

a$.$ Variable cost per unit $

b$.$ Total fixed cost