Answer:
The answer to this question is given below in the explanation section.
Step-by-step explanation:
The meaning of the sum is to add the value of the given cells. Basically,the meaning of the sum is the addition of numbers.
For example, in excel write in the formula bar, "=Sum()" its meaning is to add the value of all the given reference cells. As given in the question, "=Sum()" will add the value of the cells A2,A19, O13 and then add into 855 and 19. After all this, show the addition result in the cells where this formula is written.