### Instruction: After traveling 50 miles by taxi, Ann is charged a fare of $\$120$. Assuming the taxi fare is directly proportional to distance traveled, how much would Ann be charged (in dollars) if she had traveled 70 miles?### Response: I need to find the constant of proportionality between the fare and the distance, so I can use the formula y = kx, where y is the fare, x is the distance, and k is the constant.
I can plug in the given values of y and x for the 50-mile trip and solve for k: 120 = k * 50, so k = 120/50 = 2.4.
Now I have the constant, so I can use it to find the fare for the 70-mile trip: y = 2.4 * 70, so y = 168.
Therefore, Ann would be charged $\$168$ for traveling 70 miles.