Page 94 - Math Course 3 (Book 1)

Rate of Change and Direct Variation

5 – 1 From week 2 to week 8, the number Your Turn!
=
8 – 2 of goals changes from 1 to 5.
4 Use a Graph to Find a Constant Rate of Change
= Simplify.
6 WEATHER
2 The snow water equivalent (SWE) is a common
=
3 measure of the amount of water contained within
a snowpack. It can be thought of as the depth of
2 For every 3 week interval, water that would result if you melted the entire
Answer ; Yen increases his score by snowpack. Find the constant rate of change for
3
2 goals. the snow water equivalent in the graph shown.
Describe what the rate means.

Snow water Equivalent

Use Graphs to Identify Proportional Relationships 10

Example Snow water Equivalent (in.) 8
6

JOGGING 4
2
The distance that a jogger runs is recorded in
the table. Determine if there is a proportional 0 12 24 36 48
linear relationship between the time and distance. Snow Depth (in.)

A. 0.2; The snow water equivalent is 0.2 times the
Times(min) Distance(mi) snow depth.
x y
B. 1.2; The snow water equivalent is 1.2 times the
15 12 snow depth.

30 22 C. 2.4; The snow water equivalent is 2.4 times the
snow depth.
45 30
D. 5; The snow water equivalent is 5 times the
60 34
snow depth.
Determine if the ratio of each y-value (distance)
compared to the corresponding x-value (time) is Answer
the same.

Distance y 12 22 11 30 2 34 17
time x 15 30 = 15 45 = 3 60 = 30

distance
No, the ratio is not the
Answer time
same for every pair of values.

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