I don’t feel like solving it right now but in order to find a mean you have to add up all numbers and divide by the amount of people/objects.
If you want to solve this problem you would need to multiply 13 by 5 and then add 12, 16, 14, and 8 together and subtract it from your product of 13 and 5.
After that just check your answer by seeing if the mean of all the numbers is the same.
Parabola
It's not always easy to visualize this stuff. Do a Google image search for "3D Conic Sections" and take a look at a bunch of the results. That may help a bit. Let me know if you have any other questions.
What are u asking? what is negative fungi?
