direct variation (direct proportion)
y = kx
origin
(0,0) on graph
equivalent ratios
same part to part or part to whole relationship
constant of proportionality
ratio between 2 values is the same
variable
letter or symbol used to represent how muchdefine
k
constant of proportionality
quantity
how much
value
how much its worth
determine
what is the answer
interpret
what does it mean
define variables
figure out what they are
coordinate plane
x, y graph
horizontal
across
vertical
up an down
x,y coordinate
point on a graph
means and extremes
solve a proportion (1/2 = x/9) to find unknown quantity
discrete data
counting numbers
continuous data
values that fall between counting numbers
constant
doesn't change
constant of proportionality
the constant value of the ratio of two proportional quantities x and y
equation for proportionality
y = kx
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
origin
always where X and Y cross at (0, 0)
U.R.
unit rate
a table
a chart with X and Y boxes for numbers
a graph
grid with numbers on the X axis and Y axis to plot lines
consistent
doesn't change
3/x = 18/9
x=54
c/5 = 6/15
c=18
6/16 = 9/w
w=24
20/b = 15/9
b=12
4/9 = 12/x
x=27
30/8 = 165/t
t=44
x/1.4 = 28/5.6
x=7
y/35 = 15/14
y=37.5
x/10 = 6/4
x=15
4/3 = 9/y
6.75