Author Topic: How was your S1  (Read 8483 times)

Offline Dude22

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Re: How was your S1
« Reply #30 on: May 27, 2010, 11:21:18 am »
Same here

Like in the prob dist question with ducks

I was looking at it all wrong, trying to use binomial.
If I had used combinations I would have gotten like 4/5 marks more :(

Freaked12

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Re: How was your S1
« Reply #31 on: May 27, 2010, 11:34:29 am »
Same here

Like in the prob dist question with ducks

I was looking at it all wrong, trying to use binomial.
If I had used combinations I would have gotten like 4/5 marks more :(

hmm..
for ducks
i got the probabily for 0 geese and 1 geese
but i couldnt find out for 2 geese
but then i remembered all prababilities should equal to 1.So i added both and minused it with 1 and voila.:D


Freaked12

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Re: How was your S1
« Reply #32 on: May 27, 2010, 11:37:17 am »
tree diagram was easy i think

anyways what did you write for exclusive.i fergot the shitty formula

Offline immortal

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Re: How was your S1
« Reply #33 on: May 27, 2010, 12:17:36 pm »
The problem was that I could have aced it.
QQ.
No point regretting..
Life is short...so live it to da fullest :)

Offline Dude22

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Re: How was your S1
« Reply #34 on: May 27, 2010, 12:25:50 pm »
I got probabilities=1 but they didn't = the proof in the next part, so I know they are wrong

The tree diagram was easy
They are not independent but they are mutually exclusive, you can prove it using the formula for independent prob and ME.

I also messed up the last parts of Q7

I'm worried about p3 now since the newest P3s are hard and I make many mistakes

Freaked12

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Re: How was your S1
« Reply #35 on: May 27, 2010, 12:40:55 pm »
I got probabilities=1 but they didn't = the proof in the next part, so I know they are wrong

The tree diagram was easy
They are not independent but they are mutually exclusive, you can prove it using the formula for independent prob and ME.

I also messed up the last parts of Q7

I'm worried about p3 now since the newest P3s are hard and I make many mistakes

God damn
i fergot the exclusive and independent forumala.i lost 3 marks there.

Offline Dude22

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Re: How was your S1
« Reply #36 on: May 27, 2010, 01:16:56 pm »
Well there were 3 marks in each part

In a previous paper a similar question awarded marks like this

1 - Formula
2- Mathematical proof / calculation
3- Conclusion - eg independant or not

So if you got the rest right, but no formula you only lose 2  ;D

Offline Ykov

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Re: How was your S1
« Reply #37 on: May 27, 2010, 02:26:25 pm »
Lol, my paper was just plain ridiculous. Question 1 tried to trick us into using binomial, but it was only worth 3 marks, and my working was just plain horrible. The permutation in Question 4 was nearly impossible but I think I got the method marks for that. The rest of the paper was fine :O

Offline CHEMMASTER6000

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Re: How was your S1
« Reply #38 on: May 27, 2010, 02:52:23 pm »
its not a trick . they give 1 mark for stateing the bionomial expressoin 1 mark for subbing the correct value and a mark for answer thus 3 marks.

but true q4 is madnesss. im assuming you were doing 63 same one i did

Offline Ykov

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Re: How was your S1
« Reply #39 on: May 27, 2010, 02:59:48 pm »
You can't use binomial fyi. The probability of drawing a red sweet is not constant throughout the trial, which is a requirement to use binomial expressions. Once you draw a red sweet, the probability of drawing the next red sweet would have also changed. Thus, unless they say "the sweet was replaced after each drawing" using binomial would just be....strange and contradictory to what I've studied

Offline ammarfarook

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Re: How was your S1
« Reply #40 on: May 27, 2010, 04:08:18 pm »
Guys....can someone confirm one thing for me please....
In the graph question aka central tendency and spread of birth weights did we have to calculate:
1. Median and Interquartile range
OR
2. Mean and standard deviation
Thanks in advance!

Offline Dude22

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Re: How was your S1
« Reply #41 on: May 27, 2010, 04:31:16 pm »
Guys....can someone confirm one thing for me please....
In the graph question aka central tendency and spread of birth weights did we have to calculate:
1. Median and Interquartile range
OR
2. Mean and standard deviation
Thanks in advance!

I'm not sure

I calculated the Mean and the interquartile range, since they don't specify I'm hoping they will accept either as long as they are correct

Freaked12

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Re: How was your S1
« Reply #42 on: May 27, 2010, 04:44:01 pm »
i did median
Mode
and positive and negatively skewed

Offline Chingoo

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Re: How was your S1
« Reply #43 on: May 27, 2010, 04:53:21 pm »
I used mean, median, mode and interquartile range. Though I realized I should've also done standard deviation but I guess interquartile range will make up for it.
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Offline sweetie

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Re: How was your S1
« Reply #44 on: May 27, 2010, 05:14:05 pm »
hey ppl,
i guess i messed up in the 2nd part of Q4, how many marks waz it out of??????????

did ny1 do the last 2 parts of the permutation Q??????