I need help, please and thxs

The birch tree needs 12 years

Step-by-step explanation:

Proportional Relationship

Two variables t and d are proportional if they have the relationship described by the equation:

d = kt

Where k is the constant of proportionality.

From the graph on the question, we recognize the proportionality of the age of a birch tree and its diameter because the line passes through the origin (0,0). To find the equation, we need to recognize a clear point on the graph. We select the point (2,7). Substituting in the equation:

7 = 2k

Thus:

The equation is:

For the birch to have a diameter of d=42 inches, the time needed can be calculated by solving the equation:

t = 12 years

The birch tree needs 12 years

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.