Question

mean of 15 observation is 23. of each observation is multiplied by 2 find the new mean

Answer 1

The mean will be 2 times more . It will be 46

Answer 2

Mean of 15 observation is 23.
Therefore sum of all observations is 23×15=345.
(x+y+z....15nos.)=345

Since each observation is multiplied 2 times then,
2×(x+y+z....15nos.)
2×345=690
Mean=690/15
=46