SOLUTION:
Outliers are defined as about 1.5 times the interquartile range above the upper quarttile and below the lower quartile (Q1 - 1.5 IQR or Q3 + 1.5 IQR).
[tex]\begin{gathered} \text{IQR = Q3 - Q1 = 65 - 50 = 15} \\ outlier=Q3+1.5(15) \\ =65+22.5=87.5 \end{gathered}[/tex]
Since John's score is 81 which is below 87.5, so John is not an outlier.
