Arithmetic Mean of Frequency Distribution

&NewLine;<&excl;-- WP QUADS Content Ad Plugin v&period; 2&period;0&period;95 -->&NewLine;<div class&equals;"quads-location quads-ad1" id&equals;"quads-ad1" style&equals;"float&colon;left&semi;margin&colon;0px 0px 0px 0&semi;">&NewLine;&NewLine;<&sol;div>&NewLine;<p align&equals;"justify">&NewLine;In case of frequency distribution the raw data is arranged by intervals having corresponding frequencies&period; So if we are interested to find the mean of the data having class intervals we must know the variable x&period; This variable can be obtained by calculating the mid point of each interval&period; <&sol;p>&NewLine;<p align&equals;"justify">&NewLine;<strong>Problem&colon;<&sol;strong> Find the arithmetic mean of the data given in the table below&period;<&sol;p>&NewLine;<p> <a href&equals;"http&colon;&sol;&sol;mba-lectures&period;com&sol;wp-content&sol;uploads&sol;2010&sol;05&sol;image14&period;png"><img title&equals;"image" style&equals;"border-top-width&colon; 0px&semi; display&colon; inline&semi; border-left-width&colon; 0px&semi; border-bottom-width&colon; 0px&semi; border-right-width&colon; 0px" height&equals;"62" alt&equals;"image" src&equals;"http&colon;&sol;&sol;mba-lectures&period;com&sol;wp-content&sol;uploads&sol;2010&sol;05&sol;image&lowbar;thumb14&period;png" width&equals;"500" border&equals;"0" &sol;><&sol;a> <&sol;p>&NewLine;<p> &&num;160&semi;<&sol;p>&NewLine;<p align&equals;"justify">In frequency distribution actual values of the data are not known therefore an assumption is made that the values of the data are mid-points of the intervals&period; The calculation of these mid points and arithmetic mean&&num;160&semi; is given in the table below&period; &NewLine;<&excl;-- WP QUADS Content Ad Plugin v&period; 2&period;0&period;95 -->&NewLine;<div class&equals;"quads-location quads-ad2" id&equals;"quads-ad2" style&equals;"float&colon;none&semi;margin&colon;0px 0 0px 0&semi;text-align&colon;center&semi;">&NewLine;&NewLine;<&sol;div>&NewLine;&NewLine;<&excl;-- WP QUADS Content Ad Plugin v&period; 2&period;0&period;95 -->&NewLine;<div class&equals;"quads-location quads-ad3" id&equals;"quads-ad3" style&equals;"float&colon;none&semi;margin&colon;0px&semi;">&NewLine;&NewLine;<&sol;div>&NewLine;&NewLine;