If the mean of the following frequency distribution is 8, find the value of p.


X



3



5



7



9



11



13



F



6



8



15



P



8



4


Let’s draw the table and calculate the relative value of variables ∑xi×fi


(xi)



(fi)



(xi×fi)



3



6



18



5



8



40



7



15



105



9



P



9P



11



8



88



13



4



52




∑fi = 41 + P



∑xi×fi = 303 + 9P



By putting the formula of mean we get;


Mean = (given)


So we have,



303 + 9P = 8 (41 + P)


303 + 9P = 328 + 8P


9P-8P = 328-303


P = 25


Hence the value of the P is 25.


5