Tiara kept track of the number of good tennis serves that she made in a row.

15, 17, 9, 11, 19, 16, 12, 17

If she decides to construct a box-and-whisker plot, what is the value of the upper quartile?

First we put them in order ...

9,11,12,15,16,17,17,19

Q1 (lower quartile) = (11 + 12) / 2 = 23/2 = 11.5

Q2 (median) = (15 + 16) / 2 = 31/2 = 15.5

Q3 (upper quartile) = (17 + 17) / 2 = 34/2 = 17

so the upper quartile (Q3) = 17 <==