Answer:
[tex] IQR = Q_3 -Q_1 = 28-18 = 10[/tex]
Now we can find the limits in order to determine outliers like this:
[tex] Left = Q_1 -1.5 IQR = 18 -1.5*10=3[/tex]
[tex] Right = Q_1 +1.5 IQR = 18 +1.5*10=33[/tex]
So for this case the left boundary would be 3, if a value is lower than 3 we consider this observation as an outlier
b. 3
Step-by-step explanation:
For this case we have the following summary:
[tex] Minimum = 9[/tex] represent the minimum value
[tex] Q_1 = 18[/tex] represent the first quartile
[tex] Median =Q_2= 21[/tex] represent the median
[tex] Q_3 = 28 [/tex] represent the third quartil
[tex] Maximum=56[/tex] represent the maximum
If we use the 1.5 IQR we need to find first the interquartile range defined as:
[tex] IQR = Q_3 -Q_1 = 28-18 = 10[/tex]
Now we can find the limits in order to determine outliers like this:
[tex] Left = Q_1 -1.5 IQR = 18 -1.5*10=3[/tex]
[tex] Right = Q_1 +1.5 IQR = 18 +1.5*10=33[/tex]
So for this case the left boundary would be 3, if a value is lower than 3 we consider this observation as an outlier
b. 3