Let's assume
boiling point is y
altitude is x
we are given
This relationship between altitude and boiling point is linear
At an altitude of 1000 feet, water boils at 210°F
so, first point is (1000,210)
so, x1=1000 , y1=210
At an altitude of 3000 feet, water boils at 206°F
so, second point is (3000,206)
so, x2=3000,y2=206
now, we can find slope
![m=(y_2-y_1)/(x_2-x_1)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/25uxp4sblay2143idvgkz738ukrk1vzo5g.png)
now, we can plug values
![m=(206-210)/(3000-1000)](https://img.qammunity.org/2019/formulas/mathematics/high-school/jmzo23fzl97uyrcdcx46l6rndbvf3alg49.png)
![m=-(1)/(500)](https://img.qammunity.org/2019/formulas/mathematics/high-school/h2wsscj8kuvhl0l6opz4nyh1oiz2zlhmrn.png)
now, we can use point slope form of line
![y-y_1=m(x-x_1)](https://img.qammunity.org/2019/formulas/mathematics/college/lob8zuuisy2ohheuctatxwwco4ukatcrj3.png)
so, we can plug it
![y-210=-(1)/(500)(x-1000)](https://img.qammunity.org/2019/formulas/mathematics/high-school/i3gveilbhqkztlqpqdsval2d77y1jfwjsl.png)
so, point slope form of line is
![y-210=-(1)/(500)(x-1000)](https://img.qammunity.org/2019/formulas/mathematics/high-school/i3gveilbhqkztlqpqdsval2d77y1jfwjsl.png)
now, we can plug x=8000
and then we can solve for y
![y-210=-(1)/(500)(8000-1000)](https://img.qammunity.org/2019/formulas/mathematics/high-school/b5me5d9ired44w0tjf2124jrgjhp9i9k2x.png)
![y=196](https://img.qammunity.org/2019/formulas/mathematics/high-school/wfnvhuf32mat90o0waaq7x9ant2p92xy17.png)
So,
the boiling point of water at an altitude of 8000 feet is 196°F..........Answer