Proportion
Proportion
Proportion:
A proportion is really two ratios that are equivalent to each other. Here is an example:
There are several ways to tell if two ratios form a proportion.
1st method: Check to see if the same scale factor was used on top and bottom.
2nd method: Try and simplify one or both of the ratios.
In this example, we could reduce the second ratio. Check it out:
Once again, we can see that the two ratios are equivalent. Therefore, they must form a proportion.
3rd method: Cross products: Multiply the numbers that are diagonal to each other. If the products are equal, the two ratios form a proportion.
5 x 28 = 140
7 x 20 = 140
Check out what happens when you do not have a proportion:
2 x 45 = 90
3 x 28 = 84
Here, the cross products are not the same. This shows that the two ratios are not a proportion.
These steps are also useful in finding the missing number in a proportion.
Illustration: Here are some examples of finding the missing number in a proportion using all three methods.
1.) 
Determine if the following are in proportion : 25, 75, 80, 240 | |||
| Right Option : B | |||
| View Explanation | |||
Determine if the following are in proportion : 33, 44, 75, 100 | |||
| Right Option : A | |||
| View Explanation | |||
Determine if the following are in proportion : 32, 48, 70, 210 | |||
| Right Option : A | |||
| View Explanation | |||
Students / Parents Reviews [10]
Being a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
Prisha Gupta
8thOne of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
Aman Kumar Shrivastava
10thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Barkha Arora
10thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
10thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Shreya Shrivastava
8thA marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Archit Segal
7thIt was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Eshan Arora
8thMy experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
