Proportional Reasoning
K =
y/x
20 red cars and 4 blue cars. Whats the ratio of red to blue cars as a fraction?
20/4
What is the constant of proportionality for the graph with the following points?
(2,4) (3,6)
k = 2
1/4 = x / 16
x = 4
If I had 2 pens for every 3 pencils, how many pens would I have if I had 60 pencils?
40 pens
12 students earned A's on their math quiz and 6 earned C's. What's the ratio of A's to total as a fraction?
12/18
What is the following point on a graph called? (0,0)
The origin
35/2 = 5/x
x=3.5
Tony earns $45 for every 2 hours that he works. How much will he earn if he works 35 hours this week?
$787.50
The number of boys in a class compared to the number of girls is 4 to 5. What is the ratio of girls to boys?
5/4
Are the following points proportional? Why or why not?
(0, 0) (4, 1)
No, because there isn't a constant.
a/216 = 8/10
a=172.8
On a map, 2 inch represents 100 miles. If I wanted to represent 3.5 inches on the map, how many miles would that equal?
175 miles
Double Jeopardy!!!!
The ratio of students who prefer to watch football to basketball is 5 to 2 in Mrs. Polesnak's class. If 20 students prefer to watch football in Mrs. Holmes' class, how many students like to watch basketball?
4 students like basketball
Double Jeopardy!!!
Name three characteristics a graph must have in order for it to be proportional.
1. Go through the origin.
2. Have a straight line.
3. Have a constant
m/1.8 = 12.8/0.8
m =28.8