To find the cost \( c \) when traveling \( m = 4.5 \) miles using the equation \( c = 0.75m + 4 \), we can substitute \( m \) into the equation:
\[ c = 0.75(4.5) + 4 \]
Calculating the multiplication:
\[ 0.75 \times 4.5 = 3.375 \]
Now, we add this value to 4:
\[ c = 3.375 + 4 = 7.375 \]
Thus, the cost \( c \) for traveling 4.5 miles is \( 7.375 \).
Rounding this to the nearest hundredth, we get:
\[ c \approx 7.38 \]
So, the corresponding dependent variable \( c \) if you were to travel 4.5 miles would be $7.38.