SAT Math Multiple Choice Question 760: Answer and Explanation
The scatterplot above charts the temperature (in degrees Kelvin) and luminosity (in Suns) for 50 stars, including our own sun, that fall under the category of "Main Sequence" stars.
The vertical axis indicates the luminosity of the stars in units called "Suns." (A Sun unit equals the luminosity of our own sun.) According to the scatterplot, which of the following is the best estimate for the temperature of our sun?
- A. 2,600°K
- B. 5,800°K
- C. 10,100°K
- D. 12,400°K
Correct Answer: B
Problem Solving and Data Analysis (scatterplots) MEDIUM-HARD
Since, by definition, the luminosity of our sun is "1 sun," we must look for the number 1 on the vertical ("luminosity") axis. These numbers are given as powers of 10, so we have to remember that 100 5 1. If we trace the horizontal line representing 100 lumens, we can see that it intersects the line of best fit at roughly 6,000°K. The choice that is closest to this value is (B) 5,800°K.