Given data :
421, 175, 128, 117, 150, 145, 147, 113
Arrange the given observations in ascending order
In eight observations the 4th and 5th observations are 145 and 147.
Here, we have two middle most values 145 and 147.
Median = Average of the two middle most values
= \(\frac {145+147}{2} = \frac {292}{2} = 146\)
∴ Median of the data = 146.