What is the score range for the smallest percent of students

The score range for the smallest percent of students is:

                         400 to 700

From the pie chart or circle graph that is provided to us the smallest percent of the students are 10%

( Since 10%  is smallest among 14%,42%,34% and 10%)

and we may observe that the smallest region is denoted  or represented by the dark blue region and the range of the score of blue region that is given to us is:

                  400 to 700

   Hence, the answer is:

                   400 to 700