Construct a linear model from a description

Let \(C\) represent total cost in $, and let \(h\) represent work time in hours. One unit of \(h\) represents 1 hour

A locksmith service has an initial charge of $185. The charge then increases by $50 for each hour

Charges are proportional for fractional input units within the stated interval

The linear model is claimed for \(0 \le h \le 13\)