To calculate the interquartile range (IQR) and identify the outlier for the provided data set {35, 20, 41, 48, 79, 83, 83, 97, 120}, we'll follow these steps:
-
Order the data set:
{20, 35, 41, 48, 79, 83, 83, 97, 120} -
Calculate Q1 (the first quartile):
Q1 is the median of the first half of the data. The first half is {20, 35, 41, 48}.
Median of this half = (35 + 41)/2 = 38 -
Calculate Q3 (the third quartile):
Q3 is the median of the second half of the data. The second half is {79, 83, 83, 97, 120}.
Median of this half = 83 (since there's an odd number of data points in this segment) -
Calculate IQR (Interquartile Range):
IQR = Q3 - Q1 = 83 - 38 = 45 -
Determine outliers:
We calculate the fences to find outliers:- Lower fence = Q1 - 1.5 * IQR = 38 - 1.5 * 45 = 38 - 67.5 = -29.5
- Upper fence = Q3 + 1.5 * IQR = 83 + 1.5 * 45 = 83 + 67.5 = 150.5
Any value below the lower fence or above the upper fence is considered an outlier.
In this dataset, the only value greater than the upper fence is 120, so: -
Final Values:
- Q1 = 38
- Q3 = 83
- IQR = 45
- Outlier = 120
Now we can provide the answers to the input fields:
Q1 = 38
Q3 = 83
IQR = 45
The outlier in this data set is 120.