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Grade 9



Module 19



To be able to extract meaningful information from data

[LO 5.5]

As you know, graphs are to be seen everywhere: in advertisements, in textbooks, in magazine articles and in mathematics classes. In this section we will look at a wide selection of graphs and what we can say about the statistics they represent.

When we have only one set of values (for example the previous study of the breakfast and lunch habits of some learners), we can use a simple graph like a pie chart.

On the other hand, many graphs make a connection between two sets of values. We call this a relation.

Some examples from your previous work are: number of prison inmates in particular years; height above sea level at certain distances from a point; amount charged by a gardener for certain number of hours worked; y–values obtained from x–values substituted into a given formula; etc.

Usually this means that the graph will have a horizontal axis and a vertical axis. Just to remind you, here is the table of important words again:

Equation: x y
Equation: Independent variable Dependent variable
Flow diagram: Input value Output value
Table: First row Second row
Coordinates: 1st coordinate 2nd coordinate
Graph: x- axis y- axis
Graph: Horizontal axis Vertical axis

1 James and Gabriel are the same age – they are friends, both entering their first job at the start of January 2000. Each of them can easily take a bus to work. Each also has enough money from their holiday jobs to use as a deposit on a new car.

James wants a new car immediately, and now that he has a job, he arranges hire purchase financing for a car. He has enough for the deposit, and he can just about afford the monthly repayments. At the end of four years he replaces the car with another new one, a slightly nicer model. He again buys it on hire purchase, paying the deposit from the sale of his old car, and pays the higher instalments regularly. At the start of 2008, he does the same. Every four years he replaces his car.

Gabriel is willing to do something different. Instead of getting a new car immediately, he puts the money he would have used for the deposit into a savings account and saves up enough every month so that after four years he can buy a new car for cash. So in 2004 he chooses the same one his friend James does. Immediately he starts another savings account, making monthly payments big enough for a new car in four years’ time like the one his friend buys then. In 2008, he sells his old car when he gets the new one, and puts the money in the bank to start his savings for the next car. So he also replaces his car every four years

In other words, from 2004 they drive exactly the same cars!

The information about their expenditure is given below as a bar graph as well as a table.

Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
James 28 304 21 228 21 228 21 228 33 965 25 474 25 474 25 474 40 758 30 568 30 568 30 568 48 909 36 682
Gabriel 22 436 15 360 15 360 15 360 21 000 21 000 21 000 21 000 32 317 22 128 22 128 22 128 38 807 26 580

Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
is it a question of log
I rally confuse this number And equations too I need exactly help
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
Commplementary angles
Idrissa Reply
im all ears I need to learn
right! what he said ⤴⤴⤴
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Mathematics grade 9. OpenStax CNX. Sep 14, 2009 Download for free at http://cnx.org/content/col11056/1.1
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