Question

Eight values have a mean of 7. a ninth value is added. the new mean is 9. what is the new value

Answer 1

25 because the 8 values must times with 7 and will get 56. when the ninth value added , let the ninth value as y , 56+y , the new mean is 9 . so it will be like this , 56+y over 9 times with 9