Answer
a. 3,
b. 54,
c. no outlier
Work Step by Step
Check the data set for any data value that is smaller than Q1 - 1.5(IQR) or larger than Q3 + 1.5(IQR).
a. 16, 18, 22, 19, 3, 21, 17, 20 rearrange from lowest to highest
$IQR=20.5-16.5=4$, $1.5(IQR)=6$, $16.5-6=10.5$, $20.5+6=26.5$, one value $3$ is an outlier
b. 24, 32, 54, 31, 16, 18, 19, 14, 17, 20 rearrange from lowest to highest
$IQR=31-17=14$, $1.5(IQR)=21$, $17-21=-4$, $31+21=52$, one value $54$ is an outlier
c. 321, 343, 350, 327, 200 rearrange from lowest to highest
$Q1=\frac{200+321}{2}=260.5$, $Q3=\frac{343+350}{2}=346.5$,
$IQR=346.5-260.5=86$, $1.5(IQR)=129$, $260.5-129=131.5$, $346.5+129=475.5$, no outlier
