Answer:
Median: 88.5
Mean: 69.75
Step-by-step explanation:
Mean: add all numbers and divide by the amount of numbers.
Median: find the center most number. If none exist, take the two center most numbers and divide them by 2.
Mean: 12+88+89+90
279/4
69.75
Median:
(88+89)/2
177/2
88.5
If you write
![y=x^{1/3}](https://tex.z-dn.net/?f=y%3Dx%5E%7B1%2F3%7D)
, you'll notice this is really just a quadratic equation that can be factorized:
![2x^{2/3}+3x^{1/3}-5=0\iff 2y^2+3y-5=0\iff (2y+5)(y-1)=0\iff(2x^{1/3}+5)(x^{1/3}-1)=0](https://tex.z-dn.net/?f=2x%5E%7B2%2F3%7D%2B3x%5E%7B1%2F3%7D-5%3D0%5Ciff%202y%5E2%2B3y-5%3D0%5Ciff%20%282y%2B5%29%28y-1%29%3D0%5Ciff%282x%5E%7B1%2F3%7D%2B5%29%28x%5E%7B1%2F3%7D-1%29%3D0)
So you have
![2x^{1/3}+5=0\implies 2x^{1/3}=-5\implies x^{1/3}=-\dfrac52\implies x=-\dfrac{125}8](https://tex.z-dn.net/?f=2x%5E%7B1%2F3%7D%2B5%3D0%5Cimplies%202x%5E%7B1%2F3%7D%3D-5%5Cimplies%20x%5E%7B1%2F3%7D%3D-%5Cdfrac52%5Cimplies%20x%3D-%5Cdfrac%7B125%7D8)
and