Finding k from a table, step by step
In a proportional table the same number turns every x into its y, and that number is the constant of proportionality.
The question
x2479y12244254k
Find the constant of proportionality.
x: 2, 4, 7, 9 y: 12, 24, 42, 54
x2479y12244254
12÷2=6
24÷4=6
- In a proportional table every y is its x times the SAME number — the constant of proportionality. Find it by dividing a y by its own x.
- Take the first column: 12 ÷ 2 = 6.
- Check another column so it is not a fluke: 24 ÷ 4 = 6. Every column gives 6, so the constant is 6.
How it works.
- 01
In a proportional table every y is its x times the SAME number — the constant of proportionality. Find it by dividing a y by its own x.
- 02
Take the first column: 12 ÷ 2 = 6.
- 03
Check another column so it is not a fluke: 24 ÷ 4 = 6. Every column gives 6, so the constant is 6.