Finding k
Graphing Greatness
Table Talk
Equation Station
100

In the equation y=4x, what is the constant of proportionality

4

100

Does a proportional graph have to be a straight line?

Yes.

100

To check if a table is proportional, you must divide ___ by ___ for every row.

y/x

100

Write an equation for a relationship with a constant of 7.

y=7x

200

A table shows x=2, y=10 and x=5, y=25.  What is k?

5

200

What specific point must every proportional graph pass  through?

the origin or (0,0)

200

Is this table proportional?

x       y

2       6

3       9

10     30

yes.  k=3

200

Which equation is NOT proportional:

y=2x OR y=2x+1

y=2x+1

300

What is the k value for a relationship that passes through the point (4,10)

2.5 or 

5/2

300

On a graph, the unit rate is always found at the point (1,k).  What does k stand for?

The constant of proportionality or unit rate.

300

Fill in the missing value for this proportional table:

2     8

5     20

x     40

10

300

Rewrite 10x = 2y into the form y=kx

y=5x

400

If y is 12 when x is 3, what is the value of y when x is 7?

k = 4 so y = 28

400

What does the point (2,40) represent in a real-world context if x is hours and y is miles?

Traveling 40 miles in 2 hours.  OR  Traveling 20 miles in 1 hour.

400

In a proportional table, if x=0 what must y equal?

0

400

In the equation  y=3/4x , if x = 12, what is y?

9

500

Look at a graph where the line passes through (3,1).  What is the constant of proportionality?

1/3

500

If a graph is a straight line but passes through (0,5), is it proportional?  Why or why not?

No, because it does not pass through the origin.

500

A table has the pairs (4,2) and (10,5).  Write the equation that represents this table.

y=0.5

500

An equation represents c (total cost) for p (pounds of apples) at $1.50 per pound.  Write the equation.

c=1.50p