Answer:
The z-score for an income of $2,100 is 1.
Step-by-step explanation:
If X N (µ, σ²), then
, is a standard normal variate with mean, E (Z) = 0 and Var (Z) = 1. That is, Z
N (0, 1).
The distribution of these z-variate is known as the standard normal distribution.
Given:
µ = $2,000
σ = $100
<em>x</em> = $2,100
Compute the <em>z</em>-score for the raw score <em>x</em> = 2100 as follows:
Thus, the z-score for an income of $2,100 is 1.
something noteworthy is that the independent and squared variable in this case will be the "x", namely the graph of that quadratic is a vertical parabola.
so the parabola has solutions at x = -2 and x = 4, and its vertex will be half-way between those two guys, namely at x = 1.
since this is a vertical parabola, its axis of symmetry, the line that splits its into twin sides, will be a vertical line, and it'll be the x-coordinate of the vertex, since the vertex hasa a coordinate of x = 1, then the axis of symmetry is the vertical line of x = 1.