Question

the mean of 9 values of a data calculated as 15. if one more value is introduced in the data, the mean of 10 values becomes 16. find the 10th value

Answer 1

mean=sum of observation/(Total number of observations)

In the first case,

mean=15

Total number of observations=9

so,sum of observation=15*9=135

let new number be x

In the second case,

mean=16

Total number of observations=9+1=10

so,sum of observation=16*10=160

since we added a new number,

135+x=160

x=25