11.4 Practical Examples

Here are some real-lufe examples of uses of percentages.

• If you buy something and sell it, the difference between the two price is a profit or a loss. It is given as a percentage of the buying price.
  If you buy something for $20 and sell it for $15 you make a loss of 5% or 25%
• When you buy something you may be offered a discount.
  This is a reduction in the price. It is usually given as a percentage.
  If the price is normally $20 and you get a 10% discount, you only pay %18. 
• If a bank helps you to buy an item, you may have to pay back more than you borrow.
  This is the interest that the bank charges. It is given as a percentage of the cost.
  If the car costs $20000 and the rate of interest is 3%, you will pay $20600.
• If you buy something the price may include the tax. This is called a purchase tax.
  When you earn money you may have to pay tax on what you earn . this is called income tax.

WORKED EXAMPLE:

A man earns $45000 in a year 

He can earns $16000 withoutpaying any tax. He pays 24% tax on anything above $16000.

a) work out how much tax he pays.

b) what percetage of his income does he pay in income tax?

a) 45000 - 16000 = 29000

24% of 29000 = 6960

So he pays $6960

b) 6960 / 45000 x 100 = 15.5%

exercise 1:

1) The percentage profit is a percentage of 240

A woman bought an ols chair for $240. she told it for $300 

work out the percentage profit.

exercise 2:

1) a bottle of grape juice costs $6.50

if you buy six bottles you can get 10% discount.

Work out how much you save if you buy six bottles?

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You also may check this website below:

http://www.teacherschoice.com.au/Maths_Library/Money/profit_and_loss.htm
http://www.emathzone.com/tutorials/everyday-math/profit-and-loss.html

Check this out:

11.3 Percentage Changes

You can use percentages to describe a change in a quality. It could be an increase or a decrease. A percetage change is always calculated as a percentage of the initial value. The initial value is 100%. It is important to choose the correct value to be 100%

Worked Example :

In May 800 people visited a museum. In June 900 People visited. In July, the number was 800 again. Work out:

a) the percentage increase from May to June

b) the percentage decrease from June to July

a)  100% = 800

The increase is 100. The percentage is increase is 100/800 x 100 = 12.5%

b) 100% = 900

The decrease is 100. The percentage decrease is 100/800 x 100 = 11.1%

Exercise 1:

Here are the prices of three items in Alain's shop.

a) Game $40 

b) Phone $120

c) Computer $500 

Alain increase all the prices by $10. Find the percentage increase for each item.

Exercise 2:

"The price after the sale is $20000 again"

The price of a car was $20000. In a sale, the price decreased by 4% After the sale it increased by 4%

a) what mistake has Ahmad made?

b) What is the correct price after the sale?

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In order to be more understand you may check this web:

http://www.mathgoodies.com/lessons/percent/change.html

http://www.mathsisfun.com/numbers/percentage-change.html

http://math.about.com/od/prealgebr1/a/percent.htm

And Youtube :D 

11.2 Comparing Different Quantities

You will often need to compare that are different sizes.
Suppose that, in one school, 85 students took an exam and 56 passed.
In another school, 237 students took an exam and 147 passed.
Which school did better? It is hard to say because each school had a different number of students.

The worked example shows how to use percetages to help to answer question like this:

WORKED EXAMPLE 1:

In school A, 85 students took a mathematics exam and 56 passed.
In School B, 237 stundets took an mathematics exam and 147 passed.
Which school had a better pass rate?

59  out of 85 = 59/85 = 69%
59/85 = 0.694... = 69% to the nearest whole number.

147 out of 237 = 147/237 = 62 %
147/237=0.620... = 62% to the nearest whole number.

The pass rate in school B is better by seven percentages points!
The difference between 62% and 69% is given in 'percentage points'

Exercise 1:

There were 270 people in a cinema. There were 168 women and 102 men.
There were 152 people in the theatre. There were 78 women and 74 men.

a)  Work out the percentage of women in each venue
b)  Work out the percentage of men in each venue

Exercise 2:

This table shows the results of a survey in a factory.

	Smoker	Non-Smokers	Total
Men	12	64	76
women	9	32	41

a) what percentage of men are smoker?

b) Compare the percentages of men and women who are non-smokers?

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In order to understand you may check this website:

http://www.excellup.com/

11.1 Using Metal Methods

some percentages are easy to find because they are simple fractions.
There are examples of these on the first page of this unit.

You can use the easy ones to work out more complicated percentages.
You can often do this quite easily. You do not always need a calculator.

If you know 10% you can find any multiple of 10%

WORKED EXAMPLE:

There are 4600 people in stadium. 58% are males. How many is that?

100% = 4600

50% = 50% + 10% - 2% 
These are all easy percetages to find

50% = 2300
50% = 1/2

10% = 460
1/10 is easy. Just devide by 10

1% = 46
Divide 10% by to find 1%

58% = 2300 + 460 - (2 x 46) = 2668  
Do this sum in your head or on paper

Exercise 1:

Work Out:

a) 35% of 84
b) 49% of 230
c) 77% of 4400

Exercise 2:

Work Out:

26% of 78 = 20.28

Use this fact to find:

a) 52% of $78


b) 9.5% of 256

You may check this website if you still didn't understand:

http://www.mathsisfun.com/percentage.html
http://www.homeschoolmath.net/teaching/percent/percent_of_number_mental_math.php

Youtube:

Network Topology

Topology of a network is its physical layout. There are basically two components to a network. Devices on the network that want to share resources or information and the medium which allows the communication to occur. A Network Topology is the physical layout of the computers, servers, and cables. There are four topologies mentioned in this learning item: star, bus, mesh, and ring. You can add wireless to the list as a growing popular option for network topology.


Bus topology

 is one which consists of all of the workstations connected to a single cable. This topology is frequently in coax, or 10Base2, networks. The bus network has a terminator on each end of the network. If a terminator is not present or if there is a problem in the line (e.g. NIC card failure, network disconnected from PC), all workstations on that line lose connectivity.

The typical Bus network uses coax as its cable. Coax is a cable similar to what you use for your cable TV. Coax is also referred to as 10Base2.

The upside to using coax is that it is inexpensive, easy to install, and is not as susceptible to electromagnetic interference as twisted pair cable is.

The downside for a coax network is the speed is limited to 10 Mbps (Megabits per second) and that is an interruption occurs in the cable, all of the nodes (workstations) on the cable will lose connectivity. If a NIC fails or a cable is disconnected at any of the points in the network, it will not be terminated properly so all of the computers will lose connectivity to the network.



Mesh topology

A mesh topology is the best choice when you require fault tolerance, however, it is very difficult to setup and maintain.

There are two types of mesh network: full mesh and partial mesh. A full mesh is one which every workstation is connected to the other ones in the network. In a partial mesh, the workstations have at least two NICs with connections to other nodes on the network. Mesh networks are commonly used in WANs.

Computer Networks

 

Computer NetworksNetworks are collections of computers, software, and hardware that are all connected to help their users work together. A network connects computers by means of cabling systems, specialized software, and devices that manage data traffic. A network enables users to share files and resources, such as printers, as well as send messages electronically (e-mail) to each other.

Computer networks fall into two main types: client/server networks and peer-to-peer networks. A client/server network uses one or more dedicated machines (the server) to share the files, printers, and applications. A peer-to-peer network allows any user to share files with any other user and doesn’t require a central, dedicated server.
The most common networks are Local Area Networks or LANs for short. A LAN connects computers within a single geographical location, such as one office building, office suite, or home. By contrast,Wide Area Networks (WANs) span different cities or even countries, using phone lines or satellite links.

Networks are often categorized in other ways, too. You can refer to a network by what sort of circuit boards the computers use to link to each other – Ethernet and Token-Ring are the most popular choices. You can also refer to a network by how it packages data for transmission across the cable, with terms such as TCP/IP (Transmission Control Protocol/Internet Protocol) and IPX/SPX (Internet Package eXchnage/Sequenced Package eXchange).
Steps to Setting-Up a Network.All networks go through roughly the same steps in terms of design, rollout, configuration, and management.
Designing Your NetworkPlan on the design phase to take anywhere from one to three working days, depending on how much help you have ad how big your network is.
Here are the key tasks:

• Settle on a peer-to-peer network or a client/server network.
• Pick you network system software.
• Pick a network language.
• Figure out what hardware you need.
• Decide on what degree of information security you need.
• Choose software and hardware solutions to handle day-to-day management chores.

Rolling Out Your NetworkRolling out your network requires the following steps:

• Run and test network cables.
• Install the server or servers if you’re setting up a client/server network. (If you are setting up a peer-to-peer network, you typically don’t have to worry about any dedicated servers.)
• Set up the workstation hardware.
• Plug in and cable the Network Interface Cards (NICs – these connect the network to the LAN).
• Install the hub or hubs (if you are using twisted-pair cable).
• Install printers.
• Load up the server software (the NOS, or Network Operating System) if your network is a client/server type.
• Install the workstation software.
• Install modem hardware for remote dail-up (if you want the users to be able to dial into the network).
• Install the programs you want to run (application software).

Configuring Your NetworkNetwork configuration means customizing the network for your own use.

• Creating network accounts for your users (names, passwords, and groups).
• Creating areas on shared disk drives for users to share data files.
• Creating areas on shared disk drives for users to share programs (unless everyone runs programs from their own computer).
• Setting up print queues (the software that lets users share networked printers).
• Installing network support on user workstations, so they can "talk" to your network.

Source link : http://tecschange.org/classic/networks/network-syllabus.html

Comment: Computer network has been given us many information and help us to do our work. But, you need to be careful when you using network.

Regard,
Ndah F

What Type of Teenager Are you?

1. If you were asked by someone to hang out, what would you answer:

a. directly say 'yes'
b. think first
c. directly say 'no'


2. If you were on holidays, what would you do:

a. Hang out with friends and family
b. Stay at home (with gadgets and stuff)
c. Sleep and be lazy

3. If you were bored in the class, what would you do:

a. Skip the class
b. Talk with friends / draw / do something else
c. Sleep

4. If your teacher gave you homeworks on holiday, what would you do with it:

a. Do it on last days of the holiday
b.  Not really care if you wouldn't do it or not
c. Do it directly so you wont be disturbed by homeworks on your holiday

5. If your mother asked you to buy something in the grocery store, what would you respond:

a. Give reasons so your mother would ask another person
b. Think first to say yes or no
c. Directly say 'yes'





Result:

• If your answers are mostly A, you are a type of teenager: easy going, have and enjoy your own world, friendly with people around you, independent, care about youself more than  people around you, sometimes can be selfish but actually nice, not really open to your family, like to pretend and hide what you feel, you talk more to your friends than family.
• If your answers are mostly B,  you are type of teenager: like to play with your gadgets, sometimes can be really lazy, like to play games when you're bored, not really friendly with people around you,  have your own world in gadget (socialize in social media), think logically.Not really open to other people.
• If your answers are mostly C, you are a type of teenager: you are lazy but sometime can be dilligent, do something you rarely do if you want something really bad, spend more time on sleeping, really enjoying your life, dont care about other people opinions on you, dont rush things, relax.

Note:

based on our experience (Tsamara and Indah)

-English-

10.2 Using Statistics

Now you can work out several different statistical measures.
In a real situation, you need to decide which one to use.

If you want to measure how to spread out a set of measurements is, the range is the most statistic.

If you want to find a representative measurements, you need an average. Should it be the mode, median or the mean? That depends on the particular situation.

Here is a summary to help you decide which average to choose.

• Choose the Mode if you want to know which is the most commonly occuring number.
• The Median is the middle value, when the data values are put in order. Half the number are greater than the median and half the numbers are less than the median.
• The Mean depends on every value. If you change one number you change the mean.

WORKED EXAMPLE:

Here are the ages, in years, of the players in a football team. Work out the average age. Give a reasonfor your chioce of average.

16

17

18

18

19

20

20

21

21

32

41

• The mode id not a good choice

            There are three modes. Each has a frecuency of only 2

• The mean will be affected by the two oldest people

             They are much older and will dostort the value. In fact, the mean is 22.1 and nine people are      younger than this; only two are older

• The median is 20 and this is the best average to use in this case

            Five players are younger than the median and five are older  

10.1 Calculating Statics

You can use statistics to summarise sets of data.

You can also use to compare different sets of data.

You should already be able to calculate three different averages: 

The Mode, The Median, The Mean

Remember that the range is not an average. It measures how spread out a set of value or number is. For a large set od data, it is not practical to list every number separetly. Instead, you can record the data in frequency table.

The Mode is the most common value or number.

The Median is the middle value, when they are listed in order.

The Mean is the sum of all the values divided by the number of values.

The Range is the largest value minus the smallest.

WORKED EXAMPLE:

Number of Beads	25	30	35	40	45	50
Frequency	34	48	61	30	15	12

The tables shows the number of beads on 200 necklaces.

a) Find the mode

b) Find the mean

c) Find the range

ANSWER:

a) The Mode is 35   

    --> The mode is the number with the highest frequency

b) 6900 / 200 = 34.5 

   --> (25 x 34 + 30 x 48 + 35 x 61 + 40 x 30 + 45 x 15 + 50 x 12 ) divided by the sum of all frequencies.

          This is the middle of all the possible number of beads.

c) 50 - 25 = 25

  --> This is the difference between the largest and the smallest number of beads

Apa Kabar?

Rasanya sudah lama tidak menulis di sini. Setelah sekian banyak tugas atau project dari guru-guru yang sebenarnya terbilang cukup banyak dan membuat otak berputar 180 derajat. Tapi setelah itu liburan. Tak banyak yang berubah sekarang. Tapi banyak buanget yang berubah.

Tapi tak banyak yang bisa aku ceritakan di sini. Tapi yang jelas, guru IT yang pernah aku tulisan namanya di sini sudah pindah dari Al-Taqwa. Ya, Mr. Syaiful. Indah gak tau alasannya kenapa beliau pindah. Yah, kita memang ga perlu tahu lebih detail juga sih ya. Tapi kelas IT semakin berbeda belakangan ini tanpa hadirnya Mr. Syaiful. Beliau itu juga mantan wali kelasku ketika kelas 8 tahun yang lalu.

Kelas IT menjadi berubah sekitar 190 derajat. Kita memang masih menggunakan komputer, email, bahkan ditambah dengan kami harus membuat power point presentasi. Kalian tahu sahabat? ada sekitar 3 atau 4 presentasi yang kami buat setelah Mr. Syaiful pindah dari sini. Dikarenakan guru pengganti belum bisa masuk. Mungkin masuknya semester 2 ini.

Kemudian, project terakhir itu dari Ms. Muslimah. Kita diminta untuk membuat presentasi tentang hubungan antara Muslim dan Teknologi (komputer dan internet). Tapi membuat presentasi itu tidaklah mudah bagi kami. Karena waktu durasi sekitar 40 menit kali 2 tiap minggu itu tidak cukup. Apalagi sering dipotong durasinya karena ada Assembly. So Hard! Teman-teman di kelasku harus membagi-bagi waktu. Apalagi waktunya itu terlalu dekat dengan UAS dan project pelajaran yang lainnya juga. Dan yang tidak bersahabat lagi, ketika itu netbook yang saya pakai itu lagi kena virus. Jadi buku kesabaran extra untuk mengerjakan presentasinya.

Karena sekarang masih liburan.. Indah belum bisa menerka-nerka apa yang akan terjadi nanti. Indah berharap kelas IT akan lebih seru lagi walau sekarang tanpa adanya Mr. Syaiful. Dan Indah berharap akan ada project yang menarik dan lebih seru lagi untuk dilakukan. Dengan catatan, tidak membuat netbook anak-anak rusak.

Indah belajar, bagaimana menjaga barang sendiri itu. Memang sulit, apalagi barang elektronik. Indah merasa kapok dengan adanya virus di vivobook. Sekarang, Indah gak mau download program yang gak jelas lagi, gak mau edit video di netbook (Lemot banget lho jadinya), dan Indah ga mau pakai flaskdisk lagi kalau transfer data. Lebih baik pakai email. Local disk D Indah jadi ikutan rusak juga gara2 kebanyakan pakai flask disk. Ya, salah sendiri juga sih.. Enggak bisa anti virus. Tapi, masalahnya adalah.. Siapa yang mau beliin anti virusnya? -__-"

Mungkin di semester 2 ini nantinya, akan lebih serius atau mungkin lebih serius dari yang dibayangkan. Ahh, saya benar-benar tak peduli. Insya Allah, sepertinya ini akan menjadi semester 2 di kelas 9 ini akan menjadi semester terakhir Indah di Al-Taqwa. Hmm, benar-benar tak bisa terbayangkan.

Yah, well.. Segini aja tentang cerita yang sempat Indah tulis sekarang. Jangan lupa buat berkunjung terus ke sini ya!! :)

Salam Manis,
Ndah F