Final answer:
Mary ran the least distance out of Dan, Mary, and Ryan with a total of 2.8 miles.
Step-by-step explanation:
The student asks which of three individuals, Dan, Mary, or Ryan, ran the least distance. Dan ran 3.5 miles, Mary ran 2.8 miles, and Ryan ran more than Mary but less than Dan. Therefore, the distances run by each in order from least to greatest are Mary, Ryan, and Dan.
We can conclude that Mary ran the least distance among the three because the problem specifies that Ryan ran more than Mary and less than Dan. As Mary's distance is the smallest given value, she ran the least.