Arsey's S1 Edexcel Answers 18th Jan 2013

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I have redone the solution to Q5.

I am sorry to say but the last two parts of this question will be terribly answered by most candidates.

Reply 61

khushi96

guuys what would 67/75 be as UMS?

Reply 62

.raiden.

Original post by Mister Cery

I didnt even draw a tree diagram but i think (or hope) that if u get the answer right then it doesnt matter.

Posted from TSR Mobile

It was 4 marks two marks for working and answer 2 marks for stating which dice is thrown for each side of the coin I'm guessing

Reply 63

Arsey

Original post by Mister Cery

I didnt even draw a tree diagram but i think (or hope) that if u get the answer right then it doesnt matter.

Posted from TSR Mobile

you don't have to do a tree diagram. I wouldn't bother but I thought it would be easier to understand.

Reply 64

Polo_0

Original post by Mister Cery

I didnt even draw a tree diagram but i think (or hope) that if u get the answer right then it doesnt matter.

Posted from TSR Mobile

I didn't get the right answer lol :colondollar:

.Also is uniform distribution the same as discrete random variable??

Reply 65

GreenOut

Original post by Arsey

Finally managed to start a thread....

Q1. Standard correlation. I think the mark scheme will be very generous in part c)

Q2. DRV. Pretty easy if you revised cumulative distribution questions.

Q3. Regression. Fairly easy as it was obvious that t was x.

Q4. Normal distribution. Standard apart from c) I think that will cause a lot of problems.
I think part c) is very badly worded.

Q5. Measures of location/spread. Standard. The histogram part is very easy but always causes problems.

EDIT

parts e) and f) are going to lead to an absolute bloodbath

part e) you had to calculate the prob using normal distribution (for 2 marks!)

part f) you had to say it seems reasonable since Prob from table is 0.40 but it isn't suitable since data is skewed

I think most candidates will get 1/4 at most.

Q6. DRV/Probability. Quite a confusing question, I think this will cause quite a few problems.

Q7. Venn. I thought this was pretty easy but I can see it causing a lot of problems.

Not really sure about the grade boundaries. It seemed pretty standard. Maybe 61 for an A.

Given the bloodbath that will happen I am inclined to reduce it down to 60/75 for an A

Arsey will you be doing an S2 mark scheme?

Reply 66

YathTheMagician

guys i need an estimate of what 50/75 will be?

Reply 67

.raiden.

I thought I was sure when i put down the answer discrete uniform distribution, I thought all the probabilities were equal?

Reply 68

.raiden.

Original post by YathTheMagician

guys i need an estimate of what 50/75 will be?

67 ums

Reply 69

EL77

for question 4c the normal distribution phone charger one, would i get any marks for finding P(127<L<133)?

Reply 70

Shadskis

I said that her suggestion of using the normal distribution model was suitable because it equated to 0.4 and 240<X<400 contained 40%. How many marks would I get, if any?

Reply 71

250310

when is results out... 7th March?

Reply 72

Titus20

Original post by DJP94

Anyone like to take a shot in the dark for UMS at a raw mark of 65? Thanks in advance

Probably a little above 80. That should be an A.

Reply 73

YathTheMagician

what grade do you think 67 ums will be because i checked one of the previous jan papers they were fairly similar and it was 48 marks for a B

Reply 74

chignesh10

Original post by Arsey

I have redone the solution to Q5.

I am sorry to say but the last two parts of this question will be terribly answered by most candidates.

Is he last part 5e) and f) wrong . I got 0.4038 for e) but I am not sure?

What is the answer to part 5e).

Also for the tree diagram question, I misread teh question completely and worked out the probability of winning when you choose either die...so I got 1/3 for the blue die and 1/4 for the red die... I will lose all 4 marks won't I

Reply 75

07suppatel

For 6f i did a tree diagham but wrote as my answer avisha will win wit 1/6 if she choses the read ball
how many marks will i get out of 4

Reply 76

Steroidsman123

Original post by chignesh10

Yes e and f are wrong

Reply 77

Shadskis

I need to start reading the question a little more thoroughly before attempting it, can't believe I missed out the k=13 part (a) and (b) because I didn't read "cumulative" and just assumed they all added up to one.

Reply 78

Mister Cery

Can't believe I didn't realise 4c) was a given that question :frown:

Reply 79

EL77

guys you see the value for the skewnwss question the value was like 0.75 which is such weak skewness that the mean practically equals the median which would support normal distribution? thats what i thought, as well as using the probability value i wrote that