## College Algebra (10th Edition)

$f(12)=5.$
General formula for average rate of change from x to y: $\frac{f(y)-f(x)}{y-x}.$ Hence here: $\frac{f(12)-f(0)}{12-0}=\frac{3}{8}\\\frac{f(12)-0.5}{12}=\frac{3}{8}\\f(12)-0.5=4.5\\f(12)=5.$