This module is from Fundamentals of Mathematics by Denny Burzynski and Wade Ellis, Jr. This module discusses applications of proportions. By the end of the module students should be able to solve proportion problems using the five-step method.
Section overview
The Five-Step Method
Problem Solving
The five-step method
In
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The first and most important part of solving a proportion problem is to determine, by careful reading, what the unknown quantity is and to represent it with some letter.
The five-step method
The five-step method for solving proportion problems:
By careful reading, determine what the unknown quantity is and represent it with some letter. There will be only one unknown in a problem.
Identify the three specified numbers.
Determine which comparisons are to be made and set up the proportion.
Solve the proportion (using the methods of
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Interpret and write a conclusion in a sentence with the appropriate units of measure.
Step 1 is extremely important. Many problems go unsolved because time is not taken to establish what quantity is to be found.
When solving an applied problem,
always begin by determining the unknown quantity and representing it with a letter.
Problem solving
Sample set a
On a map, 2 inches represents 25 miles. How many miles are represented by 8 inches?
The unknown quantity is miles.
Let
number of miles represented by 8 inches
The three specified numbers are
2 inches
25 miles
8 inches
The comparisons are
2 inches to 25 miles →
8 inches to x miles →
Proportions involving ratios and rates are more readily solved by suspending the units while doing the computations.
In step 1, we let
represent the number of miles. So,
represents 100 miles.
If 2 inches represents 25 miles, then 8 inches represents 100 miles.
Try
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An acid solution is composed of 7 parts water to 2 parts acid. How many parts of water are there in a solution composed of 20 parts acid?
The unknown quantity is the number of parts of water.
Let
number of parts of water.
The three specified numbers are
7 parts water
2 parts acid
20 parts acid
The comparisons are
7 parts water to 2 parts acid →
parts water to 20 parts acid →
In step 1 we let
represent the number of parts of water. So,
represents 70 parts of water.
7 parts water to 2 parts acid indicates 70 parts water to 20 parts acid.
Try
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[link] .
A 5-foot girl casts a
-foot shadow at a particular time of the day. How tall is a person who casts a 3-foot shadow at the same time of the day?
The unknown quantity is the height of the person.
Let
.
The three specified numbers are
5 feet ( height of girl)
feet (length of shadow)
3 feet (length of shadow)
The comparisons are
5-foot girl is to
foot shadow →
h -foot person is to 3-foot shadow →
A person who casts a 3-foot shadow at this particular time of the day is
feet tall.
Try
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[link] .
is it possible to leave every good at the same level
Joseph
I don't think so. because check it, if the demand for chicken increases, people will no longer consume fish like they used to causing a fall in the demand for fish
Anuolu
is not really possible to let the value of a goods to be same at the same time.....
Salome
Suppose the inflation rate is 6%, does it mean that all the goods you purchase will cost
6% more than previous year? Provide with reasoning.
Not necessarily. To measure the inflation rate economists normally use an averaged price index of a basket of certain goods. So if you purchase goods included in the basket, you will notice that you pay 6% more, otherwise not necessarily.
Good day
How do I calculate this question: C= 100+5yd G= 2000 T= 2000 I(planned)=200.
Suppose the actual output is 3000. What is the level of planned expenditures at this level of output?
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Sekou
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Amisha
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Amisha
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Amisha
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Amisha
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Amisha
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Amisha
money as unit of account means what?
Kalombe
A unit of account is something that can be used to value goods and services and make calculations
Jim
all of you please speak in English I can't understand you're language
Muhammad
I want to know how can we define macroeconomics in one line
Muhammad
it must be .9 or 0.9
no Mpc is greater than 1
Y=100+.9Y+50
Y-.9Y=150
0.1Y/0.1=150/0.1
Y=1500
Kalombe
Mercy is it clear?😋
Kalombe
hi can someone help me on this question
If a negative shocks shifts the IS curve to the left, what type of policy do you suggest so as to stabilize the level of output?
discuss your answer using appropriate graph.