Answer:
the minimum records to be retrieved by using Chebysher - one sided inequality is 17.
Step-by-step explanation:
Let assume that n should represent the number of the students
SO,
can now be the sample mean of number of students in GPA's
To obtain n such that 
⇒ 
However ;

![E(x^2) = D\int\limits^4_2 (2+e^{-x})dx \\ \\ = \dfrac{D}{3}[e^{-4} (2e^x x^3 -3x^2 -6x -6)]^4__2}}= 38.21 \ D](https://tex.z-dn.net/?f=E%28x%5E2%29%20%3D%20D%5Cint%5Climits%5E4_2%20%282%2Be%5E%7B-x%7D%29dx%20%5C%5C%20%5C%5C%20%3D%20%5Cdfrac%7BD%7D%7B3%7D%5Be%5E%7B-4%7D%20%282e%5Ex%20x%5E3%20-3x%5E2%20-6x%20-6%29%5D%5E4__2%7D%7D%3D%2038.21%20%5C%20D)
Similarly;

⇒ 
⇒ 
⇒ 

∴ 
Now; 
Using Chebysher one sided inequality ; we have:

So; 
⇒ 
∴ 
To determine n; such that ;

⇒ 

Thus; we can conclude that; the minimum records to be retrieved by using Chebysher - one sided inequality is 17.
Answer:
C. plumber A has a greater initial value
Given two points

and

The distance between them is >>>
![D=\sqrt[]{(y_2-y_1)^2+(x_2-x_1)^2}](https://tex.z-dn.net/?f=D%3D%5Csqrt%5B%5D%7B%28y_2-y_1%29%5E2%2B%28x_2-x_1%29%5E2%7D)
The points given are (Sqrt(20), Sqrt(50)) and (Sqrt(125), Sqrt(8)), so their distance is >>>
![\begin{gathered} D=\sqrt[]{(y_2-y_1)^2+(x_2-x_1)^2} \\ D=\sqrt[]{(\sqrt[]{8}-\sqrt[]{50})^2+(\sqrt[]{125}-\sqrt[]{20})^2} \\ D=\sqrt[]{(\sqrt8)^2-2(\sqrt[]{8})(\sqrt[]{50})+(\sqrt[]{50})^2^{}+(\sqrt[]{125})^2-2(\sqrt[]{125})(\sqrt[]{20})+(\sqrt[]{20})^2} \\ D=\sqrt[]{8-2(2\sqrt[]{2})(5\sqrt[]{2})+50+125-2(5\sqrt[]{5})(2\sqrt[]{5})+20} \\ D=\sqrt[]{8-40+50+125-100+20} \\ D=\sqrt[]{63} \\ D=3\sqrt[]{7} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20D%3D%5Csqrt%5B%5D%7B%28y_2-y_1%29%5E2%2B%28x_2-x_1%29%5E2%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B%28%5Csqrt%5B%5D%7B8%7D-%5Csqrt%5B%5D%7B50%7D%29%5E2%2B%28%5Csqrt%5B%5D%7B125%7D-%5Csqrt%5B%5D%7B20%7D%29%5E2%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B%28%5Csqrt8%29%5E2-2%28%5Csqrt%5B%5D%7B8%7D%29%28%5Csqrt%5B%5D%7B50%7D%29%2B%28%5Csqrt%5B%5D%7B50%7D%29%5E2%5E%7B%7D%2B%28%5Csqrt%5B%5D%7B125%7D%29%5E2-2%28%5Csqrt%5B%5D%7B125%7D%29%28%5Csqrt%5B%5D%7B20%7D%29%2B%28%5Csqrt%5B%5D%7B20%7D%29%5E2%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B8-2%282%5Csqrt%5B%5D%7B2%7D%29%285%5Csqrt%5B%5D%7B2%7D%29%2B50%2B125-2%285%5Csqrt%5B%5D%7B5%7D%29%282%5Csqrt%5B%5D%7B5%7D%29%2B20%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B8-40%2B50%2B125-100%2B20%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B63%7D%20%5C%5C%20D%3D3%5Csqrt%5B%5D%7B7%7D%20%5Cend%7Bgathered%7D)
----------------------------------------------------------------------------------------------------------
The midpoint formula is >>>

Plugging in the points, we have >>>
You multiple 1000 by 8 and have tour answer which is 8000 per second