Answer:
The constant of proportionality is [tex]k=\frac{6}{5}[/tex]
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form [tex]k=\frac{y}{x}[/tex] or [tex]y=kx[/tex]
Let
x ----> the base of triangle
y ----> the height of triangle
To find out the constant of proportionality, divide the height by the base
First case
[tex]x=7\frac{1}{2}=\frac{7*2+1}{2}=\frac{15}{2}[/tex]
[tex]y=9[/tex]
[tex]k=\frac{y}{x}[/tex]
substitute
[tex]k=9:\frac{15}{2}=\frac{18}{15}[/tex]
Simplify
[tex]k=\frac{6}{5}[/tex]
Second case
[tex]x=10\frac{1}{4}=\frac{10*4+1}{4}=\frac{41}{4}[/tex]
[tex]y=12\frac{3}{10}=\frac{12*10+3}{10}=\frac{123}{10}[/tex]
[tex]k=\frac{y}{x}[/tex]
substitute
[tex]k=\frac{123}{10}:\frac{41}{4}=\frac{492}{410}[/tex]
Simplify
[tex]k=\frac{6}{5}[/tex]
Third case
[tex]x=16\frac{3}{4}=\frac{16*4+3}{4}=\frac{67}{4}[/tex]
[tex]y=20\frac{1}{10}=\frac{20*10+1}{10}=\frac{201}{10}[/tex]
[tex]k=\frac{y}{x}[/tex]
substitute
[tex]k=\frac{201}{10}:\frac{67}{4}=\frac{804}{670}[/tex]
Simplify
[tex]k=\frac{6}{5}[/tex]