Which is more affected by extreme observations, the mean or median? And how about the standard deviation or IQR?
mean, standard deviation
mean, IQR
median, standard deviation
medlan, IQR
Check Answer

Step 1 ：The mean is more affected by extreme observations than the median. This is because the mean is calculated by summing all the values and dividing by the number of values, so a very large or very small value can significantly change the mean. The median, on the other hand, is the middle value of a sorted list of numbers, so it is not affected by extreme values as long as they do not change the middle value.

Step 2 ：The standard deviation is more affected by extreme observations than the IQR. The standard deviation is a measure of the amount of variation or dispersion in a set of values. A low standard deviation indicates that the values tend to be close to the mean, while a high standard deviation indicates that the values are spread out over a wider range. Extreme values can significantly increase the standard deviation. The IQR, or interquartile range, is a measure of statistical dispersion, being equal to the difference between the upper and lower quartiles. IQR is a measure of variability based on dividing a data set into quartiles. Quartiles divide a rank-ordered data set into four equal parts, and values in the tail ends of the data set do not affect it.

Step 3 ：Final Answer: \(\boxed{\text{mean, standard deviation}}\)