The temperature at which water starts to boil is called the boiling point and is linearly related to altitud?

Question

The temperature at which water starts to boil is called the boiling point and is linearly related to altitude. Water boilgs at 212 degrees Farhenheit at sea leavel and 193.6 at 10,000 feet.

A.Find the Formula that relates degrees farhenheit to altitude.
B.Find the Boiling Point at an altitude of 3500 feet
C. Find the altitude if the boiling point is 200 degrees farhenheit

Try to show your work.
A.?
B.?
C.?

Answer 1

A. F=-0.00184alt+212
B. 205.56 degress fahrenheit
C. 6521.7 feet

Answer 2

If the variables are linearly related, the formula will take the form:
B = k*A + c
where B is the boiling point, A is the altitude, and k and c are some constants.

To find the constants for this formula, you need two points, ie, two values of A and B. These you have: A = 0, B = 212 and A = 10000, B=193.6.

Put these two points in your model, and now you have two equations and two unknowns, k and c. You can solve for k and c.

Of course, if you put 0, 212 you get c right away:
212 = k * 0 + c
212 = c

Now put 10000, 193.6 in to solve for k
193.6 = k * 193.6 + 212
k = -0.00184

Once you have k and c, your formula is complete. You can answer B and C by just plugging the value into your formula.

B = -0.00184 * A + 212