It decreases the number of data by one.
Answer:
vertex = (0, -4)
equation of the parabola: 
Step-by-step explanation:
Given:
- y-intercept of parabola: -4
- parabola passes through points: (-2, 8) and (1, -1)
Vertex form of a parabola: 
(where (h, k) is the vertex and
is some constant)
Substitute point (0, -4) into the equation:

Substitute point (-2, 8) and
into the equation:

Substitute point (1, -1) and
into the equation:

Equate to find h:

Substitute found value of h into one of the equations to find a:

Substitute found values of h and a to find k:

Therefore, the equation of the parabola in vertex form is:

So the vertex of the parabola is (0, -4)
Step-by-step explanation:
inner region
A=πr^2
A=π*6^2
A=π*36cm^2
A=113.09cm^2
shaded region(outer)
A=πr^2
A=π*9^2
A=π*81cm^2
A=254.46cm^2
Area of shaded region=254.46cm^2-113.09cm^2
=141.37cm^2
Mark brianliest if my answer suit your question
no it is not, 590 millimeters = 59 centimeters