13.
(a)

for x = 2:

for x = 5

(b)
The graph is:
(c)
Using the graph:



Using the quadratic formula:
Answer:
See explanation
Step-by-step explanation:
Required
The average weight produced
The question is incomplete, as the required cells are not given and there are other missing details.
However, I will give a general explanation of calculating average in Excel
The required formula is:
=AVERAGE(Cell Range)
Assume the cells that contain the boxes are: cells A10 to A10010
The average will be calculated as:
=AVERAGE(A10:A10010)
<span>Common numbers for 15 18 and 12: 1 and 3</span>
Exact form:
5/7
Decimal form:
0.71428571...