Unit Rate/Ratio/Rate/Proportion, Ch 2 Direct Variation & Constant of Proportionality, Unit Rate & Proportionality (7th math), Proportions
origin
(0,0) on graph
proportional
1. a consistent unit rate 2. straight line 3. line goes through origin (0,0)
non-proportional
1. inconsistent unit rate 2. curved line
4/3 = 9/y
6.75
Rate
A comparison of two measures which are different
Ratio
A comparison of two quantities using the same measure.
Unit Rate
A rate which is per one unit of measure such as miles per hour.
Scale Factor
The number you multiply or divide by to enlarge or shrink a photo. Also the number you multiply by to make equal ratios or solve a proportion.
Origin
The point ( 0,0) where the X and Y axes cross.
K =
The variable which represents the constant of proportionality.
reflect
To think over what you just learned and summarize it.
Proportion
Two rates or ratios which are equal.
Constant
When something does not change.
Not Proportional
When the unit rates are not equal or the straight line does not go through the origin (0,0).
Axis
X is the horizontal axis and Y is the vertical axis
a table
a chart with X and Y boxes for numbers
horizontal
across
origin
always where X and Y cross at (0, 0)
20/b = 15/9
b=12
c/5 = 6/15
c=18
k
constant of proportionality
discrete data
counting numbers
consistent
doesn't change
constant
doesn't change
define variables
figure out what they are
a graph
grid with numbers on the X axis and Y axis to plot lines
quantity
how much
value
how much its worth
variable
letter or symbol used to represent how muchdefine
Butterfly method
method used to solve a proportion in which you cross-multiply (then divide) to get the equivalent ratio
Scale down
method used to solve a proportion in which you divide to get the equivalent ratio
Scale up
method used to solve a proportion in which you multiply to get the equivalent ratio
x,y coordinate
point on a graph
constant of proportionality
ratio between 2 values is the same
equivalent ratios
same part to part or part to whole relationship
means and extremes
solve a proportion (1/2 = x/9) to find unknown quantity
30/8 = 165/t
t=44
constant of proportionality
the constant value of the ratio of two proportional quantities x and y
U.R.
unit rate
vertical
up an down
continuous data
values that fall between counting numbers
6/16 = 9/w
w=24
interpret
what does it mean
determine
what is the answer
coordinate plane
x, y graph
x/10 = 6/4
x=15
4/9 = 12/x
x=27
3/x = 18/9
x=54
x/1.4 = 28/5.6
x=7
direct variation (direct proportion)
y = kx
equation for proportionality
y = kx
y/35 = 15/14
y=37.5