What disadvantage(s) are there of the mean deviation?

A. based on only two observation

B.can be distorted by a large mean

C. not in the same units as the original data.

D.has no disadvantage

E. none of the above.

To determine the disadvantages of mean deviation, let's go through each option:

A. The mean deviation is not based on only two observations. It considers the deviation of each value from the mean of the data set. So this option is incorrect.

B. Mean deviation can be influenced by extreme values (outliers) in the data set, just like the mean. If there are large outliers, the mean deviation may be distorted. Therefore, this option is correct.

C. Mean deviation is measured in the same units as the original data. Unlike other measures like standard deviation that have squared units, mean deviation retains the same units as the data set. So this option is incorrect.

D. This option states that mean deviation has no disadvantages, which is not true. As discussed in option B, it can be distorted by a large mean, so this option is incorrect.

E. Based on the analysis above, option B is correct, indicating that there is at least one disadvantage of mean deviation. Therefore, the correct answer is B.