Answer
$y=-0.00186x+212.213$
$186.2^{\circ}\text{F}$
Work Step by Step
We use a graphing calculator to plot the points $(x,y)$ from the given data and the best-fitting line (see graph).
The equation of the best-fitting line provided by the graphing calculator is:
$$y=-0.00186x+212.213.\tag1$$
Use Eq. $(1)$ to calculate the boiling point $y$ when the elevation is $x=14,000$:
$$y=-0.00186(14,000)+212.213\approx 186.2.$$
So the boiling point at an elevation of $14,000$ ft is approximately $186.2^{\circ}\text{F}$
