Answer:
B. 68% of the molecules have speeds between 450 meters/second and 550 meters/second.
Step-by-step explanation:
Since there is a standard deviation of 50 meters per second, and the mean speed is 500 meters per second, the speeds would range between 500 - 50 meters per second and 500 + 50 meters per second, which would be a range of 450 to 550 meters per second.
If you remember the Empirical Rule (68-95-99), things that are one standard deviation from the mean are within 68% of the data. Two standard deviations would include 95% of the data. Three standard deviations would include 99% of the data. Since this question just covers one standard deviation, 68% of the molecules have speeds between 450 meters per second and 550 meters per second.
Hope this helps!
