Lesson 6: Rates Ration and Proportions Flashcards
What is a ratio?
A comparison of two like quantities by division
A ratio can be expressed with a ______ or ______
Colon
As a fraction
The ________ in which the ratio is written is _______
Order
Important
Both terms of a ratio must have the same _____
Unit
What is a type of ratio that compares two unlike quantities?
Rate
What is a Unit Rate?
A rate in which the denominator is 1 unit.
For the cost of an Item, unit rate is called?
Unit Cost
To find a unit rate you must ______________________________
divide by the number of the quantity that follows the word per
A proportion is an
equation that state that two ratios are equal
In the Proportion A:B = C:D (A/B = C/D) the terms A and D are
extremes
In the Proportion A:B = C:D (A/B=C/D) the terms B and C are
Means
In proportions, the product of the means and the product of the extremes are called
Cross Products
When one term in a proportion is not know one must,
- use a variable in its place
2. Cross multiply and solve for the variable
Finding a value of a variable in a proportion is called?
solving the proportion
a proportion is true when?
- Cross products are equal
2. both ratios of the proportion are the same when written in simplest form
Two variables X and Y, are directly ___________ if the ratio of Y to X is a non zero ______
Proportional
constant
Directly Proportional Ratios can be express by the equation
Y/X = K or Y=K•X where K is a nonzero number
In the equation Y/X = K, K is called _____ or ______
the constant of variation
Constant of proportionality
What is the equation for Directly Proportional?
X1/Y1=X2/Y2 , which become (x1)(y2)=(x2)(y1)
When two variables, X and Y, are ___________ the product of X and Y is a nonzero _______
Inversely proportional
Constant
X•Y=K or Y=K/X
The equation for Inversely proportional is
X1/Y2=X2/Y1 which becomes (X1)(Y1)=(X2)(Y2)
Direct Proportion means
that two quantities increase or decrease in the same ratio
Inversely proportion means
a relation between two quantities such that one increases in proportion as the other decreases.