Answer:
90
Explanation:
mean is basically taking the sum of all numbers and then dividing the sum with the number of all given numbers..
here, the mean is 9, total numbers are 10.. so the sum will be 9 multiplied by 10, that is 90.
Answer:
2800 [MPa]
Explanation:
In fracture mechanics, whenever a crack has the shape of a hole, and the stress is perpendicular to the orientation of such, we can use a simple formula to calculate the maximum stress at the crack tip
Where 
is the magnitude of he maximum stress at the tip of the crack, 
is the magnitude of the tensile stress, 
is 
the length of the internal crack, and 
is the radius of curvature of the crack.
We have:
![r_{c}=1.9*10^{-4} [mm]](https://tex.z-dn.net/?f=r_%7Bc%7D%3D1.9%2A10%5E%7B-4%7D%20%5Bmm%5D)
![l_{c}=3.8*10^{-2} [mm]](https://tex.z-dn.net/?f=l_%7Bc%7D%3D3.8%2A10%5E%7B-2%7D%20%5Bmm%5D)
![\sigma_{c}=140 [MPa]](https://tex.z-dn.net/?f=%5Csigma_%7Bc%7D%3D140%20%5BMPa%5D)
We replace:
![\sigma_{m} = 2*(140 [MPa])*(\frac{\frac{3.8*10^{-2} [mm]}{2}}{1.9*10^{-4} [mm]})^{0.5}](https://tex.z-dn.net/?f=%5Csigma_%7Bm%7D%20%3D%202%2A%28140%20%5BMPa%5D%29%2A%28%5Cfrac%7B%5Cfrac%7B3.8%2A10%5E%7B-2%7D%20%5Bmm%5D%7D%7B2%7D%7D%7B1.9%2A10%5E%7B-4%7D%20%5Bmm%5D%7D%29%5E%7B0.5%7D)
We get:
![\sigma_{m} = 2*(140 [MPa])*(\frac{\frac{3.8*10^{-2} [mm]}{2}}{1.9*10^{-4} [mm]})^{0.5}=2800 [MPa]](https://tex.z-dn.net/?f=%5Csigma_%7Bm%7D%20%3D%202%2A%28140%20%5BMPa%5D%29%2A%28%5Cfrac%7B%5Cfrac%7B3.8%2A10%5E%7B-2%7D%20%5Bmm%5D%7D%7B2%7D%7D%7B1.9%2A10%5E%7B-4%7D%20%5Bmm%5D%7D%29%5E%7B0.5%7D%3D2800%20%5BMPa%5D)
ANSWER:
Your best bet would be to either contact apple support or to factory reset the iphone
