Rates are used to show how a quantity measures over another.
Andy does not read at a constant rate.
The table is given as:
![\left[\begin{array}{cccccc}x&10&20&30&40&50\\y&4&9&10&15&20\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccccc%7Dx%2610%2620%2630%2640%2650%5C%5Cy%264%269%2610%2615%2620%5Cend%7Barray%7D%5Cright%5D)
Pick any two points from the table:
![(x_1,y_1) = (10,4)](https://tex.z-dn.net/?f=%28x_1%2Cy_1%29%20%3D%20%2810%2C4%29)
![(x_2,y_2) = (20,9)](https://tex.z-dn.net/?f=%28x_2%2Cy_2%29%20%3D%20%2820%2C9%29)
The rate (m) is then calculated as:
![m = \frac{y_2 - y_1}{x_2 - x_1}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7By_2%20-%20y_1%7D%7Bx_2%20-%20x_1%7D)
So, we have:
![m = \frac{9-4}{20-10}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B9-4%7D%7B20-10%7D)
![m = \frac{5}{10}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B5%7D%7B10%7D)
![m = 0.5](https://tex.z-dn.net/?f=m%20%3D%200.5)
Pick another point from the table
![(x_1,y_1) = (10,4)](https://tex.z-dn.net/?f=%28x_1%2Cy_1%29%20%3D%20%2810%2C4%29)
![(x_2,y_2) = (30,10)](https://tex.z-dn.net/?f=%28x_2%2Cy_2%29%20%3D%20%2830%2C10%29)
The rate (m) is then calculated as:
![m = \frac{y_2 - y_1}{x_2 - x_1}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7By_2%20-%20y_1%7D%7Bx_2%20-%20x_1%7D)
![m = \frac{10 - 4}{30 - 10}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B10%20-%204%7D%7B30%20-%2010%7D)
![m = \frac{6}{20}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B6%7D%7B20%7D)
![m = 0.3](https://tex.z-dn.net/?f=m%20%3D%200.3)
The rates calculated are not equal
<em>i.e. 0.3 and 0.5 are not equal</em>
This means that;
Andy does not read at a constant rate.
Read more about rates at:
brainly.com/question/13103052