The Distance Formula squares the differences between the two x coordinates and two y coordinates then adds those squares and finally takes their square root to get the total distance along the diagonal line. Heres how we get from the one to the other. Unknown value to find.
The Distance Formula is a variant of the Pythagorean Theorem that you used back in geometry.
The distance of a point from a line is the length of the shortest line segment from the point to the line. For a discrete probability distribution the mean is given by where the sum is taken over all possible values of the random variable and is the probability. When you know the coordinates. This will also be perpendicular to the line.