Given:
Two points that are close to the line of best fit are (2,70) and (4.5, 90).
To find:
Th equation of best fit line using the given two points.
Solution:
We know that, if a line passes through the two points, then the equation of line is
![y-y_1=(y_2-y_1)/(x_2-x_1)(x-x_1)](https://img.qammunity.org/2021/formulas/mathematics/college/2ft4curll9g1xqqt5yfsd57zfqfj5z775i.png)
Two points (2,70) and (4.5, 90) are close to the best fit line.
Consider the two points (2,70) and (4.5, 90). So, the equation of line is
![y-70=(90-70)/(4.5-2)(x-2)](https://img.qammunity.org/2021/formulas/mathematics/college/o15b9v1mh423to5q1rngkhd7hxwfk3zp7s.png)
![y-70=(20)/(2.5)(x-2)](https://img.qammunity.org/2021/formulas/mathematics/college/rv7s2ou0jhb0nwi7a2av0lyjft9twxkc5c.png)
![y-70=8(x-2)](https://img.qammunity.org/2021/formulas/mathematics/college/affmzb5o1w4y0faoh1u8eadt9ny9mbu803.png)
![y-70=8x-16](https://img.qammunity.org/2021/formulas/mathematics/college/nf9muzz7ozyxxzo01is29p8yoxichpulnn.png)
Adding 70 on both sides, we get
![y=8x-16+70](https://img.qammunity.org/2021/formulas/mathematics/college/r1324uo5p1cegm8m11r5kdkhrz8z2mvgno.png)
![y=8x+54](https://img.qammunity.org/2021/formulas/mathematics/college/fxqvclzzg8ltf8tyzy0p5dar41wh0kvcux.png)
Therefore, the equation of best fit line is
.