The temperature at which water starts to boil is called its boiling point and is linearly related to the altitude. water boils at 212degreesf at sea level and at 193.6degreesf at an altitude of 10 comma 000 feet.

Answer : The complete question is attached in the answer.

Answer A) In the given equation of T = M x + b; where T is the temperature in degrees fahrenheit, and x is altitude in thousands feet;

Now, at sea level altitude will be 0, so x = 0

Here the equation will become; T = M (0) + b

Where T is 193.6 and, b=212 and if it is at 10,000 feet x = 10;

Substituting in equation we get; 193.6 = 10M +212,

On solving we get M = -18.4,

So, T = -1.84 x + 212 ...(the required relationship).

Answer B) Now we have to the temperature at the altitude of 3,500 feet above sea level,

here x becomes 3.5 and we have T as 193.6 and M as -1.84 so substituting the values in the equation we get,

T = -1.84 (3.5) + 212 = 205.56 F ,

Hence Temperature will be = 205.56 F.

Answer C) In the given question we have to find the altitude if the boiling point is 200 F

So, T was 212 and now it is 200 so we have to calculate the altitude;

Equation is T = M x + b; so x = (T-b) / M;

Substituting the values in this rearranged equation,

x = (200-212) / -1.84 = ~ 6522 ft

So, the altitude may be 6522 feet