Statement (I) Range depends on minimum and maximum value only. So, it will not be affected by intermediate observations.
Statement (II) It is true 4 that the mean deviation of an ungrouped data about the median is always less than or equal to the value of the mean deviation computed about any other measure of central tendency. Statement (III) For a grouped data, range is approximated as the difference between lowest (minimum) value and the largest (maximum) value of the given data or among all given class interval. Statements I, II are true but III is false.