168 cubic inches
or 180cm3
The numbers inside the parenthesis is the value of x, uses the equation associated with the value of x and solve.
H(1) Since 1 fits 1≤x≤3 use x^3
x^3 1^3 = 1
h(1) = 1
h(4) 4 fits x >3, so use 5
h(4) = 5
If you are asking for the formula thing, it is
y=3x+2