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Reply 100
another thing, that cumulative freq. + boxplot question. the total of people was 40 afaik, so first of all to find the median i figured you divided /2 which =20, but then you add .5 on because it's a whole number or smth? anyway then i thought to my revision book which didn't say to do this. i've looked on the net, some sites are saying it's the exact middle value (ie 20 not 20.5) but a couple are saying that you do move it up .5. i'm confused, cos my book does say after checking that with an example of a cum freq graph, a max of 120 means the median is taken exactly at 60 (so not 60.5 then!¬).
wat exactly were the answers to the last question.....i'm pretty sure it was sinx+1 but the other, was it 2sinx or sin2x? and the last last question? wat the hell did u hav to say?
Reply 102
God how do u people remember all those questions? and the marks for them as well?
would you get all 5 marks for getting the answer 83% as opposed to 83.3333%???


thanks....
vinz
another thing, that cumulative freq. + boxplot question. the total of people was 40 afaik, so first of all to find the median i figured you divided /2 which =20, but then you add .5 on because it's a whole number or smth? anyway then i thought to my revision book which didn't say to do this. i've looked on the net, some sites are saying it's the exact middle value (ie 20 not 20.5) but a couple are saying that you do move it up .5. i'm confused, cos my book does say after checking that with an example of a cum freq graph, a max of 120 means the median is taken exactly at 60 (so not 60.5 then!¬).


We've been told to get the median by "adding one, dividing by two" It always works that way...
Reply 105
Fleff
We've been told to get the median by "adding one, dividing by two" It always works that way...
yeh that's what i've been told aswell (well, differerntly, but with same outcome as your method), except that contradicts with that i've seen in my book and on the net (learn.co.uk and the TTA site) :/ in the end i just did what my book said and just divide it /2 ie none of this adding or whatever business. guess we'll never find out :wink:

would you get all 5 marks for getting the answer 83% as opposed to 83.3333%???


thanks....
for some reason i put 84% as my answer, even though i calculated that i needed to do 100%-16.6recurring. think i just got overwhelmed with the paper and didn't think straight. we should definately get method marks at least, it's just a case of whether they give us Benefit of Doubt or not :frown:
Reply 106
urban_flavaz
wat exactly were the answers to the last question.....i'm pretty sure it was sinx+1 but the other, was it 2sinx or sin2x? and the last last question? wat the hell did u hav to say?


it was sinx+1, but the whole graph had been moved along 90 degrees, cos sin touches the x axis at 180 and this one touched it 270.i didnt know how you were sposed to put the +90degrees in the equation tho.
it was a difficult question esp. the last one where u had to explain the movement....oh well....hopefully the calc mite be easier :rolleyes:
I didn't think it was too bad apart from the probablility one (everyone found that hard) and the surd one (Surds have NEVER sunk in with me!). I actually found the Mr Patel car price one extremly easy until the last part which I couldn't do!


I got the stupidest answer ever for the probability one:

'Explain why the probablility of getting a white ball cannot be 2/5'

Because there are 7 white balls and 7 is a prime number so the numerator of the fraction must be 7.

lol I bet you now know how much I didn't get that question!
Reply 109
shyopstv


I got the stupidest answer ever for the probability one:

'Explain why the probablility of getting a white ball cannot be 2/5'

Because there are 7 white balls and 7 is a prime number so the numerator of the fraction must be 7.

lol I bet you now know how much I didn't get that question!


I put something of similar stupidity. I wrote that 2, 5 and 7 do not have common multiples, forgetting of course 70, 700, 7000 etc....
Reply 110
i thought the car one was kinda ok, did you 1600 and .5? when i was trying to explain why the guy's probability was wrong, i went on but odds and evens and prime numbers...completely messed up that paper.HELL im gona fail!
neha p
i thought the car one was kinda ok, did you 1600 and .5? when i was trying to explain why the guy's probability was wrong, i went on but odds and evens and prime numbers...completely messed up that paper.HELL im gona fail!

yea the car one was 1600 and 0.5...pretty sure of that. for the probability question i put sumthin like 7/n+7 = 2/5 and then worked out the value of n. i got 10.5 and so said the guy is wrong. i have no idea if this is rite or not... :confused:
Reply 112
how did you work out the 5 mark probability one?i have seen a variaion of solutions..dont know which is correct?
well, i drew a tree diagram then done sumthin like (7/n+7 x n/n+7)+(7/n+7 x n/n+7) but got lost along the way....doubt its rite
Reply 114
yh, i did that too, but didnt get how you can get 2x^2-35x+98=0!!
did you do the second bit of that question?i got completely lost by then, i just guessed an answer.really really hope the next paper isnt as impossible.
i couldnt....i left it out cos i had no idea wat 2 do because i didnt get that 5 mark question rite! yea, 'hopefully' next week's paper will be much easier....and if its not they mite lower the grade boundaries, neva knw
Reply 116
consolation...last years paper was so hard that apparently you needed 40% for a c!!maybe i can get my A then.how did you do on the last question? did you get sinx+1?
Reply 117
neha p
how did you work out the 5 mark probability one?i have seen a variaion of solutions..dont know which is correct?


I have put my solution here.
yea, it was definatly sinx+1 but the 2nd graph was either 2sinx or sin2x.....not sure which 1....i crossed out 1 and put the other cos i had no idea. the last question where u had 2 explain was tough. didnt get it. did u?
Reply 119
urban_flavaz
yea, it was definatly sinx+1 but the 2nd graph was either 2sinx or sin2x.....not sure which 1....i crossed out 1 and put the other cos i had no idea. the last question where u had 2 explain was tough. didnt get it. did u?


It was y = sin x + 1

And y = 2 sin x

The explain question was for y = 3 sin 2 x

The answer was:

The graph has been stretch parallel to the y axis by a factor of 3 and then stretched parallel to the x axis by a factor of 1/2.

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