To find the mid-way number we do this:
find the difference between the highest number and the lowest given number.
Divide the difference by 2
Add that number to the lowest number or subtract that number from the highest number.
20,000 - 4,632 = 15,362

= 7,684
4,632 + 7,684 = 12,316
or (we get the same number)
20,000 - 7,684 = 12, 316
12,316 is between 4,632 and 20,000
The slope of the line is 2 if that is what you're looking for
Domain is all the x values (2,-1,4,-3)and range is the y values (0,4,2,0)
It’s is 997/1000. Just put the number over the highest decimal place
Answer:
Therefore the friends will have to buy 511 feet of fence (rounding up) or 510 feet of fence ( to the nearest foot).
Step-by-step explanation:
i) perimeter of rectangular yard = 319 feet
ii) perimeter of yard of friends 
iii) Therefore the friends will have to buy 511 feet of fence or 510 feet of fence ( to the nearest foot).