SAT question dae126d7 (Linear Functions)

Question

The boiling point of water at sea level is $21 2^{\circ}$ Fahrenheit. For every $550$ feet above sea level, the boiling point of water is lowered by about $1^{\circ}$ Fahrenheit. Which of the following equations can be used to find the boiling point $B$ of water, in $^{\circ}$ Fahrenheit, $x$ feet above sea level?

147

Difficulty:Medium

A

$B = 550 + \frac{x}{212}$

B

$B = 550 - \frac{x}{212}$

C

$B = 212 + \frac{x}{550}$

D

$B = 212 - \frac{x}{550}$

College Board · Accepted Answer

The correct answer is D. Choice D is correct. It's given that the boiling point of water at sea level is 212 ^° Fahrenheit and that for every 550 feet above sea level, the boiling point of water is lowered by about 1 ^° Fahrenheit. Therefore, the change in the boiling point of water x feet above sea level is represented by the expression -x/(550) . Adding this expression to the boiling point of water at sea level gives the equation for the boiling point B of water, in ^° Fahrenheit, x feet above sea level: B = 212 - x/(550) .

CookSAT · Answer

Note: The regression uses sea level and 550 feet higher to fit the starting value 212 and rate -1/550.

Explanation

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Why the other choices are wrong

SAT Question dae126d7: Linear Functions answer and explanation with Desmos solution

Explanation

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Why the other choices are wrong