As a data analyst, you are mapping out a fixed monthly software licensing fee over time. Time in months is plotted on the x-axis, and the fee in thousands of dollars is on the y-axis. Because the fee never changes, its graph forms a perfectly horizontal line. If one of the data points from your historical records is $(-1, 4)$, which equation correctly models this horizontal line?

A technician is calibrating a sensor that monitors a constant voltage. The voltage $y$ is graphed against time $x$. The path of the constant voltage forms a horizontal line passing through the recorded data point $(-1, 4)$. Arrange the following steps in the correct order to determine the mathematical equation of this line using the point-slope method.

In a logistics report, a fixed delivery fee is modeled as a horizontal line on a coordinate plane where the $y$-axis represents the cost in dollars. If this line passes through the point $(-1, 4)$, the equation representing the fixed delivery fee is $y = 4$.

Horizontal Line Elevation in Civil Engineering

An HVAC technician is monitoring the temperature of a specialized cold-storage unit. The temperature is maintained at a constant level, which appears as a horizontal line on a digital monitoring grid. If the line passes through the point $(-1, 4)$, the equation that represents this constant temperature line is ____.