First convert the distance she ran from a mixed number to a improper fraction:
2-3/4 equals 11/4.
Since this a unit rate problem divide the miles by the time traveled.
11/4 (miles) ÷ 1/3 (hour). When you divide a number by a fraction use (Keep-Change-Flip).
11/4 × 3/1 = 33/4 miles/hour.
Convert improper fraction to mixed number by dividing 33 by 4.
33/4 = 8-1/4 miles/ hour.