Mean deviation of a frequency distribution is least when it is measured from

Which one of the following is NOT a graphical presentation of a frequency distribution?

The given figure represents which type of frequency distribution? (Figure: a frequency curve with a long tail to the right; Mode, Median and Mean marked from left to right)

The sum of deviations of a set of observations x₁, x₂, ...., xₙ measured from 50 is −10 and the sum of deviations from 46 is 70, then the number of observations is

Deciles and percentiles divide the frequency distribution in (p, q) equal parts. Then (p, q) are

Which one of the following is NOT a measure of dispersion?