Question

The mean of 15 observation is 16.4 .If one observation is cancelled , the mean of remaining data is 17. The cancelled observation is ______

Answer 1

given mean of 15 observations  = 16.4
 sum of all abseravations/number of observations=16.4
sum of all observatins/15=16.4
sum of all observations=16.5 *15
                                 = 247.5
if 1 observation is cancelled
         ,mean = 17
sum of all observartions=17*14
                                   =238
so the cancelled observation = 247.5 - 238
                                          =9.5