Question

The table shows the temperature (y) at different altitudes (x). This is a linear relationship. Use the equation y = -0.004x + 69 to determine the temperature at an altitude of 5,000 feet. Altitude (ft), x Temperature (°F), y 0 69 2,000 61 4,000 53 6,000 45 8,000 37 10,000 12,000 29 21 The temperature at an altitude of 5,000 feet is

Answer 1

Given the expression:

$y=-0.004x+69$

To determine the temperature at an altitude of 5000 feet, we have to make x=5000 and then see what happens to 'y':

$\begin{gathered} x=5000 \\ \Rightarrow y=-0.004(5000)+69 \\ \Rightarrow y=-20+69=49 \\ y=49 \end{gathered}$

Therefore, the temperature at an altitude of 5000 feet is 49 °F