4: Ratios & Proportionality
A Ratio is a comparison of two quantities.
Example: There are 18 daisies and 6 roses.
What is the ratio of daisies to roses: (we can write this 3 ways)
a) 18 : 6 b) 18 to 6 c) 18 /6
What is the ratio of roses to daisies:
a) 6 : 18 b) 6 to 18 c) 6/18
A Rate is a ratio that compares two quantities measured in different units.
Example: The car travels 130 miles every 2 hours
What is the Rate: 130 m/2 hr
A Unit Rate is a rate whose denominator is 1.
How fast does the car travel every hour?:
130 m / 2 hr = 65 m / 1 hr or 5/6 mile / 1/3 hr = 2 1/2 mile / 1 hr
Divide the fraction to find the unit rate.
- Lesson 4.2 Notes
Watch Notes Here being filled out
Video on Constant Rate of Change from a table HERE
Video Find k from a table. Note: they use "r" instead of k.
WATCH THIS VIDEO: Click here
Practice HERE finding the constant of proportionality
- Lesson 4.3 notes
Video on write an equation from a table
Practice writing an equation from a table
Video if a graph is proportional find k and the equation
Practice finding constant of proportionality, (k), in a graph
