Find the missing frequency (p) for the following distribution whose mean is 7.68.


x:



3



5



7



9



11



13



y:



6



8



15



p



8



4




X



y



yx



3



6



18



5



8



40



7



15



105



9



P



9p



11



8



88



13



4



52




N = p + 41



∑yx = 9p + 303



Given,


Mean = 7.68


= 7.68


= 7.68


9p + 303 = 7.68 (p + 41)


9p – 7.68p = 314.88 – 303


1.32p = 11.88


p = = 9


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