Example 1: Fill in the table with the order pairs for the ratios that describe the number of CDs to their cost. Then graph the ordered pairs and describe the pattern.
Cost to Create CDs
Number of
CDs, x
1
Cost in
Dollars, y
3
Ordered
Pair (x, y)
(1, 3)
2
3
6
9
(2, 6)
(3, 9)
Pattern: The points form a straight line. Each point is one unit to the right and three units up from the previous point. So, the cost increases by $3 for every CD created.

Example 2: Two friends are making scrapbooks. Ren é e places 4 photos on each page of her scrapbook. Gina places 6 photos on each page of her scrapbook. How do the ratios to each page for person compare?
Renée’s Scrapbook Gina’s Scrapbook
Pages, x Photos, y (x, y) Pages, x Photos, y (x, y)
3
4
1
2
12
16
4
8
(1, 4)
(2, 8)
(3, 12)
(3, 16)
3
4
1
2
6
12
18
24
(1, 6)
(2, 12)
(3, 18)
(3, 24)
Comparison: The ratio of photos to pages for Renée’s scrapbook is 4:1 while the ratio of Gina’s is 6:1. On the graph, both sets of points are in a straight line but Gina’s points are steeper than Renée’s.

The table below shows Gloria’s earnings for 1, 2 and 3 hours.
Fill in the ordered pairs column of the table. Then, graph the ordered pairs and describe the pattern in the graph.
Hours, x
1
2
3
Gloria’s Earnings
Dollars
Earned, y
5
Ordered
Pair (x, y)
( , )
10
15
( , )
( , )
Pattern:

Two friends are each saving money in their bank accounts. Marcus saves $10 each week while David saves $15 per week. Complete each table. Then, graph each person’s ordered pairs.
Marcus’ Savings
Weeks, x Savings, y (x, y)
1
2
10
20
( , )
( , )
3
4
30
40
( , )
( , )
David’s Savings
Weeks, x Savings, y (x, y)
1
2
15
30
( , )
( , )
3
4
45
60
( , )
( , )
How do the ratios of Marcus’ savings and
David’s savings compare?