The "mean" is the same thing as the "average".
To get the average, you add up all the numbers on the list,
then divide the big sum by the number of items on the list.
If there are 100 numbers on the list, then in order to find their average,
you would add up all 100 numbers, then divide the big sum by 100.
If you wound up with an average of 51.18, then you must have had
5,118 just before you divided it by 100. So the big sum is 5,118.
Answer:
The correct option is A.
Step-by-step explanation:
The difference between actual value and predicted value is called residual.
Formula of residual is
Where, y is observed value or actual value and 
is predicted value.
The value of residual is 1.4 and option A is correct.
The ratio of boys to girls is 3/5.
