Calculate the mean deviation about median from the following data: 340, 150, 210, 240, 300, 310, 320.

Explanation

$$M.D. about median =\sum_{i=1}^{n} \frac{\left|x_{i}-M\right|}{N}$$
$$\sum_{i=1}^{n}\left|x_{i}-M\right|=|340-240|+|150-240|+|210-240|$$
$$+|240-240|+|300-240|+|310-240|$$
$$[phone]$$
$$=100+90+30+0+60+70+80$$
$$=430$$
$$M.D. about median =\frac{430}{7}=61.428$$