Answer:
The IQR (interquartile range) of 13 is the most accurate measure of variability to use in this case, since the data is skewed and contains some outliers.
The IQR is a measure of variability that is less sensitive to extreme values than the range, and is calculated as the difference between the upper and lower quartiles (the 75th and 25th percentiles). It provides a measure of the spread of the middle 50% of the data, which is useful for understanding the typical range of donations received.
In this case, the IQR is calculated as follows:
- The median of the data is 51 (the value in the middle).
- The lower quartile (Q1) is the median of the lower half of the data, which is 42.
- The upper quartile (Q3) is the median of the upper half of the data, which is 54.
- The IQR is the difference between Q3 and Q1: IQR = Q3 - Q1 = 54 - 42 = 12.
So the IQR of 13 is a useful measure of variability to use for this data set, since it captures the spread of the middle 50% of the data while being less sensitive to the outliers at the higher end of the distribution.