the mean of n value is 8 if a new value 28 is includded the mean becomes 9. find the of n.
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1 Answer

???? yu hav sum numbers with averaej=8,

then add 28 & nu averaej=9 ???

averaej=sum/(num numbers)=sum/n

(sum+28)/(n+1)=9     & sum/n=8

equashun 1: sum+28=9n+9

eqiasjim 2     sum=8n

subtraks...28=n+9, so n=28-9, so n=19

sum=8*19=152, nu sum=152+28=180 & 180/20=9

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