Mode of value inside a modal class = $l$ + $({f_1-f_0}/{2f_1-f_0-f_2})× h$ where $l$ = lower limit of the modal class, $h$ = size of the class interval (assuming all class sizes to be equal), $f_1$ = frequency of the modal class, $f_0$ = frequency of the class preceding the modal class, $f_2$ = frequency of the class succeeding the modal class.