Reagan surveyed a number of her classmates about what time they usually go to bed. of the fifteen classmates she asked, nine said 10 p. m. what central angle measure would you use to represent this group on a circle graph?

A pie chart

Explanation:

A pie chart can simply be used to measure and represent her observation. From the given parameters;

the total number of students = 15

Number of students that said 10pm = 9

using the pie chart; we take each measure to be fraction of the angles in a circle.

Angle subtended by the 9 students  = x 360 = 216°