In thefollowing frequency distribution, the frequency of the class interval (40-50) is not known. Find it, if the arithmetic mean of the distribution is 52. {:("Wages(Rs.)",10-20,20-30,30-40,40-50,50-60,60-70,70-80),("Number of Workes"," "5," "3," "4," "?," "2," "6," "13):}

In thefollowing frequency distribution, the frequency of the class int

1.	In thefollowing frequency distribution, the frequency of the class interval (40-50) is not known. Find it, if the arithmetic mean of the distribution is 52. {:("Wages(Rs.)",10-20,20-30,30-40,40-50,50-60,60-70,70-80),("Number of Workes"," "5," "3," "4," "?," "2," "6," "13):}
Answer» Solution : `BARX=(sumfm)/(sumf)` `52=(1,765+45f)/(33+f)` `Or, 52(33+f)=1,765+34f` `1,716+52f=1,765+45f` `52f-45f=1,765-1,716` `rArr""7f=49` `rArr""f=7` MISSING FREQUENCY =7.