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Post by Sag E Dargah E Jilani on Oct 5, 2009 18:08:23 GMT
Well I need your peoples help inshallah  I hope we have people who like the maths  tauba tauba.  Can someone tell me me how to do the the frequncy polygons, from the below data 0-10 11-20 21-30 31-40 41-50 I know how to do the midpoint etc just dont know how to find the frequncy....please help  |
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Post by Sister Nomee on Oct 5, 2009 20:42:06 GMT
Well I need your peoples help inshallah I hope we have people who like the maths tauba tauba. Can someone tell me me how to do the the frequncy polygons, from the below data 0-10 11-20 21-30 31-40 41-50 I know how to do the midpoint etc just dont know how to find the frequncy....please help As much as I would love to help but sorry I was not very good at maths,  Come on you Mathematicians help the young brother out. Wa'alaykum 'Assalam wa Rahmatullahi wa Barakatuhu |
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Bint e Attar
Senior Member
Duniya kare par tu na karna muj ko rad.. Ya Allah..
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Post by Bint e Attar on Oct 5, 2009 21:15:48 GMT
Assalamu 'Alaykum wa Rahmatullahi wa BarakatuhuThere was a time when I used to love math and now it makes me go  So sorry cant help u.. and I'm sure jub tak koi reply kare tab tak problem solve hochuki hogi..
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Post by Sag E Dargah E Jilani on Oct 6, 2009 6:42:26 GMT
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Post by farheen on Oct 6, 2009 14:48:47 GMT
Well I need your peoples help inshallah I hope we have people who like the maths tauba tauba. Can someone tell me me how to do the the frequncy polygons, from the below data 0-10 11-20 21-30 31-40 41-50 I know how to do the midpoint etc just dont know how to find the frequncy....please help I hope this helps 
Your data appear to be discrete, such as marks in a test out of 50. We will assume here that the data are test marks. Normally, in GCSE Maths, a frequency polygon shows the Frequency on the y-axis plotted against the Mark. Your data are grouped and so the mark used to plot a point is the midpoint value of the group. For example, the midpoint mark of the second group, 11-20, is 15.5, obtained by calculating the mean of the two values, 11 and 20. Therefore, the second group is represented on the graph by a point plotted at mark=15.5 and frequency=5. The next point along (the third group) is plotted similarly at mark=25.5 and frequency =12, and so on.There is a slight problem with the first group (0-10), but leave that for the moment. As with plotted points on any graph, you should show each point clearly with a cross (× or +). The axes must be clearly labelled (such as Frequency and Mark) and a suitable scale chosen. The x-axis scale can start at 0 with equally spaced divisions as in 0, 10, 20 etc. The frequency axis starts at zero (always) with a scale such as 0, 2, 4, etc, up to 12.
If the first group started at 1 instead of 0, it would be similar to the other groups and contain 10 possible values, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. The midpoint of that is 5.5. Because it starts at zero there are 11 possible values and so the midpoint is 5, the mean of 0 and 10. Therefore the first point on the graph is plotted at 5 and not 5.5.
A frequency polygon is a line graph and so to complete the graph you join the plotted points by straight lines. In GCSE Maths there is no need to continue the line of the graph beyond the first and last points.
For an explanation and example graphs of frequency polygons, see pages 11 and 12 of:
www.edu-sol.co.uk/histograms/hist…
There is a further problem with the first group (0-10) which you may prefer to ignore. Because the group contains 11 possible values and the others contain 10, the first group is wider. If you are doing the higher tier you will know that for groups (classes) with unequal width, you should plot frequency density, not frequency, on a histogram. The same applies to frequency polygons. In AS Maths you would be expected to plot frequency density for a frequency polygon with unequal class widths. See, for example page 17 of this advanced level online book:
books.google.co.uk/books?id=Y4IJu…
For example, for the second and subsequent groups, the width is 10. The frequency density for the second group is frequency 5 divided by width 10 (5/10) equals 0.5. But for the first group the density is frequency 2 divided by 11 giving approx 0.18. Having calculated the densities you then plot frequency density, not frequency, on the y-axis. This is a complication that you may prefer to ignore and stick with frequency.
Fi Amanillah |
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Post by Saalik on Oct 6, 2009 15:34:11 GMT
Haafiz Saahib, sorry  |
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bintyhawa
Senior Member
meray peer di har dam khair howay
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Post by bintyhawa on Oct 6, 2009 16:57:40 GMT
Assalamu 'Alaykum wa Rahmatullahi wa Barakatuhu
have you got a scenario for the data?
Wa'alaykum 'Assalam wa Rahmatullahi wa Barakatuhu
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Naseeruddin Qadri
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My Lord is looking at my heart. I must keep it excellent for Him.
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Post by Naseeruddin Qadri on Oct 6, 2009 17:10:53 GMT
lolz. During my school days I used to do maths if I get headache. Though I do not remember exactly frequency polygons as I guess I studied it some 11yrs back. But I would like give my view here Frequency polygon is one method of showing a frequency table in a graph. It is made as follows - The frequency polygon uses a linear graph paper
- The X-axis represents the class interval and hence the scores.
- The Y-axis shows the frequency.
- The mid point of the class interval or the class mark represents the average score or value of the class interval.
- Each frequency point from the frequency table is plotted correctly with respect to the X and the Y co-ordinates.
- The points thus plotted are joined sequentially. They thus make a frequency polygon.
So in short you need to have Class, midpoint of the class and frequency to plot frequency graph. For example =========================================== Class---------------mid point of class--------Frequency =========================================== 0-10-----------------------5---------------------somevalue 11-20---------------------15---------------------somevalue 21-30---------------------25---------------------somevalue 31-40---------------------35---------------------somevalue 41-50---------------------45---------------------somevalue ============================================ Plot mid point of the class on the X-axis and the frequency on the Y-axis. You will get a set of points, Join the points one after another to obtain the frequency polygon. Mid point calculation: ================= midpoint = sum of class intervals / 2 example : in first case (0+10) /2 = 5 in second case (11+20) / 2 = 15.5 (I guess we need to select floor of the value here.) Frequency calculation: ================== You will be give some data in the actual problems, like weights of items or ages of person etc. From the problem you need to figure out what could be maximum and minimum values. If percentage of marks are given then minimum can be 0 and maximum can be 100. This helps in dividing class intervals. You need to count the number of values in the give data that belongs to a particular class and that will give you frequency example : given data is 3,8, 10,19, 35,24,16, 48 dividing the class here in the interval of 10 --------------------------- class frequency --------------------------- 0-10 ------ 3 -- (3,8,10) 11-20 ------ 2 -- (16,19) 21-30 ------ 1 -- (24) 31-40 ------ 1 -- (35) 41-50 ------ 1 -- (48) Plot mid point of the class on the X-axis and the frequency on the Y-axis. You will get a set of points, Join the points one after another to obtain the frequency polygon. Hope this helps you. Correct me if I am mistaken. Sorry for the poor tables drawn. I am not sure about table support in this editor, it says I need to disable my pop up blocker. Even then I could not see the table. Wa'assalam |
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Post by Sag E Dargah E Jilani on Oct 6, 2009 20:22:33 GMT
Jazkallah for sharing but Inshallah I think I will just ask my teacher |
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Post by Sister Nomee on Oct 6, 2009 20:44:52 GMT
Jazkallah for sharing but Inshallah I think I will just ask my teacher Hope he/she is not an oldie ;D Brother o4husi remember old is gold and one day you too will reach that oldie stage inshAllah!!  Wa'alaykum 'Assalam wa Rahmatullahi wa Barakatuhu |
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Post by Saalik on Oct 6, 2009 20:59:47 GMT
Brother o4husi remember old is gold and one day you too will reach that oldie stage inshAllah!! Yes Haafiz Saahib and you'll be in the same position  as some  |
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Post by Sag E Dargah E Jilani on Oct 7, 2009 6:36:43 GMT
oh yeah she is an oldie. thats why i never ask her in the first place as she comes into anger really quickly if you dont understand the maths old people get angry really quickly....saalik bhai do you also have a short fuse???  |
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Naseeruddin Qadri
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My Lord is looking at my heart. I must keep it excellent for Him.
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Post by Naseeruddin Qadri on Oct 8, 2009 4:46:59 GMT
Brother o4husi, did your problem got solved.
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Post by farheen on Oct 8, 2009 13:59:08 GMT
Bismillahir Rahmanir Raheem Assalamu 'Alaykum wa Rahmatullahi wa BarakatuhuI hope this helps [....] Did u do this on ur own.. or did u used google..?? If its the first then u just proved brother 04husi wrong.. Only if they have the guidance of buzurg log Hmm dear sis bint e adam.....  .....so ur calling me oldie....'buddi'   ...... Fi Amanillah |
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Bint e Attar
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Duniya kare par tu na karna muj ko rad.. Ya Allah..
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Post by Bint e Attar on Oct 8, 2009 14:24:17 GMT
Assalamu 'Alaykum wa Rahmatullahi wa BarakatuhuHmm dear sis bint e adam..... .....so ur calling me oldie....'buddi' ...... Fi Amanillah No sis.. I wouldnt do that not even in my dreams.. 
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Post by Saalik on Oct 8, 2009 16:33:31 GMT
No sis.. I wouldnt do that not even in my dreams.. Trust me Sister Farheen, you can trust her  |
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Post by Sag E Dargah E Jilani on Oct 8, 2009 21:21:20 GMT
Brother o4husi, did your problem got solved. Nope  Chalo I will inshallah pick marks from the rest of the paper. |
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Naseeruddin Qadri
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My Lord is looking at my heart. I must keep it excellent for Him.
Posts: 287
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Post by Naseeruddin Qadri on Oct 9, 2009 4:39:43 GMT
Brother o4husi, did your problem got solved. Nope Chalo I will inshallah pick marks from the rest of the paper. Give me full data about the problem. Initial data will be a list of numbers (example indicating percentages, ages etc...) InshaAllah I shall try to solve that problem. These are very simple problems you should know its answer. |
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Post by farheen on Oct 9, 2009 8:25:36 GMT
No sis.. I wouldnt do that not even in my dreams.. Trust me Sister Farheen, you can trust her Never mind dear  |
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Ki Nighabani Mein!
