Means in statistics means that when we add all  the given numbers together and divide it with the by the total number of the given numbers. For example : The tatal results of students in ss 2 A is listed above :15,18,22 and 20
 When we add all the numbers together and =75
The total number of the test rusult is =4
We will divide 75 by 4 which will be =18.75 and this will be our answer.
1 5 1
this simply means average
Yeah you are right