Study Guide for Ratios/Proportions/Percents Test
Things to remember:
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BEGIN EVERY PROBLEM WRITING YOUR GIVEN RATIO WITH THE UNITS!!!!
DO NOT FORGET TO INCLUDE UNITS ON GIVEN RATIOS/RATES AND UNIT RATES!!!!!
UNIT RATE MUST INCLUDE UNITS!
𝑦
Ratios are setup as 𝑥
To find unit rate divide the number in the denominator into the numerator. (Numerator goes first in your calculator)
For unit price the money always goes on top.
To solve for a missing piece - setup the ratios as a proportions and cross multiply
When dividing fractions you must show your steps – write it as division problem then keep, change, flip.
𝑦
A table is proportional if all ratios (written ) simplify to the same value.
𝑥
A graph is proportional if it is straight and goes through the origin.
A table is setup with x being the first column and y the second.
The constant of proportionality is the constant which shows the situation is proportional. (it is the number in the top of your
unit rate)
COP does NOT include units and is NOT written over a 1.
Your equation is written in the form y=mx, where m is replaced by the constant of proportionality.
To make a table you need to know the COP or unit rate to compute the other values. You can also plug values into your
equation to get the missing values.
%
𝑖𝑠
To calculate percent’s you can either use the percent equation or setup the proportion: part = % × whole or 100 = 𝑜𝑓
Discount is subtracted, tax is added, tip is added.
Discount is subtracted from original price to give you the subtotal. The tax is found then added to subtotal which gives you the
total. Add tip to the total.
Commission is found by multiplying the percent of commission to amount they made commission off of.
Find the unit rate or unit price for the following:
1. Marcus types 135 words in 3 minutes. How many words can he type per minute?
2. Isabella spent $66 on 11 new hair bows. How much was each hair bow?
Solve the proportions for the missing variable.
3.
𝑚
8
21
= 56
4.
7
=
2
63
𝑥
5. If there are 420 calories in 7 servings, how many calories are there in 11 servings?
6. Solve:
4⁄
5
6⁄
7
7. Michael wants to buy a surfboard that costs $645. The surf shop is having a store-wide 25% off sale.
a. How much will he save (discount)? _____________
b. What is the sales price (subtotal)? _____________
c. What will he pay after the 7% sales tax (total)? _______________
8. Maya took her family to dinner. The bill was $57. He left the server an 18% tip.
a. How much was the tip?_______________
b. What did he spend total at the restaurant?_______________
Fill in the missing representations.
Table:
Graph:
Equation:
Verbal:
There are 180 seats in 6 rows.
Fill in the following components for the given situation.
10. An ice-cream factory makes 210 gallons in 2 hours.
Ratio: _____________________________
Unit Rate: _______________________
Constant of Proportionality: ___________
Equation:________________________
11. Is the table shown below proportional?
If it is, what is the COP? _______________
12. Is the graph shown below proportional?
If it is, what is the COP? _______________
13. What is the sales price of a $185 skateboard that is discounted 30%?
14. The salesman sold a car for $42,000. How much is the commission if the salesman makes 2% of the sale?
15. What is 20% of 150?
16. 64 is what percent of 200?