The following questions relate to grouped data and its central tendency measure called the mode.
(a) What is meant by:
(i) grouped data, and
(ii) the modal class of a grouped frequency distribution?
(b) While determining the mode of grouped data, why is it necessary to know the frequencies of the classes immediately preceding and succeeding the modal class?
(c) In a grouped distribution, suppose two class intervals have the same highest frequency. State a suitable criterion that can be applied to decide which of these classes should be considered as the modal class and briefly justify your answer.