Ratios & Rates
What is the unit rate? 280 miles: 10 gallons
28 miles: 1 gallon
Do 9/12 and 6/8 form a proportion? How do you know?
Yes! They are both equivalent to 3/4, or 72=72
Solve 15/2 = 30/y
y= 4
Tell whether x and y show direct variation. Explain y= x + 3
No, it is not in y=kx form
What is the unit rate? 6.4 revolutions in 2 seconds
32 revolutions per second
Do 4/9 and 2/3 form a proportion?
no, 12 does not equal 18
Solve x/4 = 2/5
x= 1.6
Tell whether x and y show direct variation, when y=6x Explain. What is amount they are related by?
Yes! This is in form of y=kx
k=6
What is the unit rate? 960 calories to 8 servings of the meal
120 calories to 1 serving
Solve 8/20 = 6/w
w= 15
Where on the coordinate plane do all proportional relationships begin or pass through>
What is the origin or (0,0)
There are 15 orangutans and 25 gorillas in a nature preserve. One of the orangutans swings 75 feet in 15 seconds on a rope. a. What is the ratio of orangutans to gorillas? b. How fast is the orangutan swinging?
a. 3: 5 b. 5 ft per second
Solve (s+1)/4 = 4
s=15
Does x + y =20 show direct variation? Explain
No, when solved it is y = -x +20, not y=kx
What one way to solve proportions never fails?
Cross product method, or cross multiplying
You are 13 years old and your cousin, Andy is 19 years old. As you grow older, is your age proportional to your cousin's age? Explain.
No, the ratios are not equivalent 13/19 does not equal 14/20 etc.
There are 180 white lockers in the school. There are 3 white lockers for every 5 blue lockers. How many total lockers are in the school?
480 lockers
Does, y-x = 0 show direct variation?
Yes, this is in the form y = x or y = 1x, which is the direct variation form.