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Statistics S1 post your doubts here
- Thread starter IGCSE13
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http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w09_qp_61.pdf
Can anyone PLEASE explain Q3 ii)
Can anyone PLEASE explain Q3 ii)
thanks alot
can you please help me with mean questions
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s13_qp_63.pdf Q6 (iii)
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_63.pdf Q3 (iii)
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_61.pdf Q6 (iv)
In these above listed questions for finding mean we make intervals. So can you please tell how to make intervals in these questions.
of (weight
Mark and no of pupils )
If you have done these questions can you PLEASE take the pictures and upload them.
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ok, first of all we need to realize that the intervals for calculating means are defined such that the lower boundary of any class is the same as the upper boundary of the former class. So, for the weight question, first thing is to quickly define classes, that is the 40 will become 0-39 then 40-49 , 50-59, 60-64, 65-69, 70-89, now in order to allign them you need to take average of the upper of one and lower of other so the first one will become 0<x<(39+49)/2 => 0<x<39.5 similar stuff will be done to others. Now once they are aligned and i think this shouldn't take more than two minutes, calculate mid values of the interval by averaging the upper and lower class boundary of each interval, then define frequency of each interval which is c.f. of the interval - c.f. of the previous interval.
you now have the required data to calculate the mean which has formula E(fx) / E(f) which means sum of the product of each f and its corresponding x divided by the total frequencies which we already know by the c.f table. A similar approach is required in other questions aswell
Standard deviation = sq.rt [(E(fx^2)/E(f)) - ((E(fx)/E(f))^2]
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well i know most of the people find permutations and combinations a pain in the butt 
.Well i just found some notes which i found xtremely helpful...so im like 'hey y not share them with ppl' ..PLEASE I HAVE MY A2 EXAMS (phy, p3 ,s1 and chem p5 left) soooo pleeeeeeeeeeeeeeeeeeeeeeez pray fr me here it is http://www.bmlc.ca/PureMath30/Pure Math 30 - Combinatorics Lesson 2.pdf
http://www.bmlc.ca/PureMath30/Pure Math 30 - Combinatorics Lesson 1.pdf
.Well i just found some notes which i found xtremely helpful...so im like 'hey y not share them with ppl' ..PLEASE I HAVE MY A2 EXAMS (phy, p3 ,s1 and chem p5 left) soooo pleeeeeeeeeeeeeeeeeeeeeeez pray fr me here it is http://www.bmlc.ca/PureMath30/Pure Math 30 - Combinatorics Lesson 2.pdfhttp://www.bmlc.ca/PureMath30/Pure Math 30 - Combinatorics Lesson 1.pdf
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http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w11_qp_62.pdf
Question 3(b)..PLEASE Quick.
Question 3(b)..PLEASE Quick.
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http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w11_qp_62.pdf
Question 3(b) PLEASE quick.
Question 3(b) PLEASE quick.
The key word in this question is that they are asking only for 2 of the 3 G to be together
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w13_qp_61.pdf Q1 do we have to do it on a graph paper ? And can someone please sketch it for me
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Few doubts...
1) The spelling is GREENGAGE not GREENAGE.
2)Why didn't you consider the first place for double Gs before the first letter. If we consider the first place the total becomes 7 instead of 6.
I
If you consider the first place then 3Gs will be together and the question is asking for 2Gs to be together only
Sorry about the spelling thing I was in a hurry
If you consider the first place then 3Gs will be together and the question is asking for 2Gs to be together only
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Thank you SO much. I was stuck with this question since decades. Highly appreciated.
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You are not required to find the mean and standard deviation in this question but if you are asking in general then the mean can be found by creating a CF table from the graph since you have the upper bounds on the x axis and the respective CF on the y axis then you can work out the frequencies ,class boundaries and midpoints
I have no idea how to calculate the sd sorry
Probability of houses with numbers greater than 14 =5/12 (16,18,20,22,24)
Probability of at least 2=probability of 2 or 3
Probability of 2=5/12*4/11*7/10 *3!/2! (3! Because they can be chosen in any order but you have to divide it by 2! because two of the options are same )
Probability of 3 = 5/12*4/11*3/10
And you add both of them together
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I am a little bit confused in this area , I am trying to sort it out right know and I will let you know as soon as I do
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Sorry for my bad handwriting.
For the second part of this question you can also use normal distribution to find probability as you have got the (sd in the first part)
