Answer:
Sandy, she ate 42.85% of the bag.
Explanation:
Divide the numerator by the denominator for each person.
Kim - 3÷10= 0.3 (30%)
Sandy - 3÷7= 0.4285714286 (42.85%)
Jeff - 3÷9= 0.333333 (33.33%)
*Remember when dividing fractions 1=100%, ie, 4/2= 200%, 5÷10= 50%*