Hey there!
Here is a graph of the points:
A scatterplot is a graph, but the points won't be able to connect in a straight line, and they have no relation.
A line of best fit is a line that goes evenly through the points, or as best as it could.
Ten to the third power / 3/10th
Inequality: 20+40n≤260
Graphing inequality is in the picture I posted.
Answer:

Step-by-step explanation:
Given two non zero vectors,
.
Let the angle between the two vectors = 
Given that:

Let us have a look at the formula for magnitude of addition of two vectors:

Where
is the angle between the two vectors.
formula for magnitude of subtraction of two vectors:

As per the given condition:

Squaring both sides:

So, the angle between the two vectors is: 
I went through the process and got 6