[AspiringGenius]

Hey TSR,

Firstly, a big good luck to anybody taking C1 today and anybody else taking exams

I have seen exam angst/discussion threads about most subjects- just hought S1 could have one.

So, anybody on TSR doing it? Got any tips? And burning questions? I'm sure it would be fine to post here

AspiringGenius

[the bear]

(Original post by AspiringGenius)
Hey TSR,

Firstly, a big good luck to anybody taking C1 today and anybody else taking exams

I have seen exam angst/discussion threads about most subjects- just hought S1 could have one.

So, anybody on TSR doing it? Got any tips? And burning questions? I'm sure it would be fine to post here

AspiringGenius

Hi aspiring !! Are you doing c1 today ?

[AspiringGenius]

I'm not, I'm taking it in June I want to take it now I dislike stats

[AspiringGenius]

TSR isn't telling me there's no one taking this exam?

[uttamo]

I'm supposed to be taking this one. It's fine I'm just a bit rusty on hypothesis testing and probability. Also, percentiles. Ok I should get revising then.

[mohammeda134]

easy ways to get your head round hypothesis testing? anyone?

[uttamo]

Reject H0 when the probability of whatever is in the tail (or critical region). Accept H0 anywhere else.

[AspiringGenius]

Hypothesis testing: the only way you can reject the truth with an innumerate amount of evidence. Bane of my life.

[AspiringGenius]

Anybody there're???????

[Minotauro]

Do any of you guys have a link to the june 2011 s1 paper

[themaddesthatter]

i'm taking this and i'm so worried i barely get half the stuff ESPECIALLY probability and permutations/combinations :/ i really want 90 ums but there is no way that is going to happen

[glitterphobia]

I'm also retaking this! completely messed up last time and walked out half-way through. hardly revised AT ALL. been too busy concentrating on biology (which i'm still behind on too).
aaaaaaaaaaargh!

Here's some basic bits to remember:

Categorical - non-numerical, discrete - listed, continuous - can't list.
Stem&Leaf - discrete/continuous.
Vertical Line - discrete
Histogram - continuous, frequency proportional to area

Mean = sum of x divided by n (in grouped, sum of xf divided by n)
Median = (n + 1)/2th item (Q2 in box and whisker) 1/2n
Lower quartile = Q1, median of lower half, 1/4n (Q3 is same, just upper half/upper quartile, 3.4n)
Interquartile range = Q3 - Q1
Mode = most common (modal class, class with most data when equal width).
Mid-range = half of min + max.
Range = max - min
Sum of squares = sum of (x - x^2) (in grouped, sum of (x - (mean)^2f))
Mean Square Deviation = sum of squares/n
Root Mean Square Deviation = square root of above
Variance = sum of squares/n - 1
Standard Deviation = square root of variance.
Outlier = more than 2s away from mean (or more than 1.5 x interquartile range beyond lower/upper quartile).

P(A) = n(A) / n(E) (n(A) = no. of ways A can occur, n(E) = all poss events).
P(A U B) = P(A) + P(B) - P(A n B) (mutally exclusive, P(A n B) = 0, so just P(A U B) + P(A) + P(B).
P(A) + P(A') = 1
P(B|A) = P(A n B)/P(A)
P event A then event B = P(A) x P(B|A)
If event B independent of event A = P(B|A) = P(B|A') = P(B).

Discrete random variable, X with values r1, r2... and P p1, p2, p3 etc = sum of p1 to pn = sum of k=1 to n P(X = rk) = 1; pi > 0.
Expectation E(X) = sum of rP(x = r).
Variance Var(X) = sum of r^2P(X = r) - (E(X))^2

No. of ways of arranging n objects in line = n!
n! = n x (n - 1) x (n - 2) x... x 3 x 2 x 1.
No. of permutations of r objects to n, nPr = n!/(n - r)!
No. of combinations of r objects from n, nCr = n!/(n - r)! r!
Permutations - order matters, combination - order doesn't matter.
0! = 1.

P(X = r) = nCr x q^n-r x p^r.
B(n, p) expectation of no. of successes = np.

Hypothesis testing, check:
1. Test set up before/after data known?
2. Sample chosen at random/independent?
3. Does it test original claim?

Steps for hypothesis testing:
1. Establish null and alternative
2. Decide significance
3. Collect data (random so items independent)
4. Conduct test
5. Interpret result in terms of original claim.

That's about it.

Some resources:
http://learn123.co.nr/ms1.php (my website with video tutorials for MEI)
http://www.mei.org.uk/files/papers/MEI_S1.pdf (all past papers)
http://www.mei.org.uk/files/pdf/formula_book_mf2.pdf (formula book)

[glitterphobia]

(Original post by themaddesthatter)
i'm taking this and i'm so worried i barely get half the stuff ESPECIALLY probability and permutations/combinations :/ i really want 90 ums but there is no way that is going to happen

permutations/combinations are actually pretty easy, i was struggling to until i realised: combinations don't need an order, permutations do.
also, to work them out just use the nPr button on the calculator for permutations and nCr for combinations.

[nddm10]

how do you know when to use n and n-1 when calculating the standard deviation? (it's sometimes very unclear from past papers)

[cemead1]

What do you think will come up? I'm pretty sure that there will be
a graph to draw
conditional probability like a venn diagram
some sort of nCr and nPr
E(x) and Var (x)
mean and standard deviation
hypothesis test (i reckon it'll be critical regions.)

[themaddesthatter]

how did everyone find it?? i made some dumb errors cos i had to do d1 before it and lost al my concentration argh

[ss2012]

(Original post by glitterphobia)
I'm also retaking this! completely messed up last time and walked out half-way through. hardly revised AT ALL. been too busy concentrating on biology (which i'm still behind on too).
aaaaaaaaaaargh!

Here's some basic bits to remember:

Categorical - non-numerical, discrete - listed, continuous - can't list.
Stem&Leaf - discrete/continuous.
Vertical Line - discrete
Histogram - continuous, frequency proportional to area

Mean = sum of x divided by n (in grouped, sum of xf divided by n)
Median = (n + 1)/2th item (Q2 in box and whisker) 1/2n
Lower quartile = Q1, median of lower half, 1/4n (Q3 is same, just upper half/upper quartile, 3.4n)
Interquartile range = Q3 - Q1
Mode = most common (modal class, class with most data when equal width).
Mid-range = half of min + max.
Range = max - min
Sum of squares = sum of (x - x^2) (in grouped, sum of (x - (mean)^2f))
Mean Square Deviation = sum of squares/n
Root Mean Square Deviation = square root of above
Variance = sum of squares/n - 1
Standard Deviation = square root of variance.
Outlier = more than 2s away from mean (or more than 1.5 x interquartile range beyond lower/upper quartile).

P(A) = n(A) / n(E) (n(A) = no. of ways A can occur, n(E) = all poss events).
P(A U B) = P(A) + P(B) - P(A n B) (mutally exclusive, P(A n B) = 0, so just P(A U B) + P(A) + P(B).
P(A) + P(A') = 1
P(B|A) = P(A n B)/P(A)
P event A then event B = P(A) x P(B|A)
If event B independent of event A = P(B|A) = P(B|A') = P(B).

Discrete random variable, X with values r1, r2... and P p1, p2, p3 etc = sum of p1 to pn = sum of k=1 to n P(X = rk) = 1; pi > 0.
Expectation E(X) = sum of rP(x = r).
Variance Var(X) = sum of r^2P(X = r) - (E(X))^2

No. of ways of arranging n objects in line = n!
n! = n x (n - 1) x (n - 2) x... x 3 x 2 x 1.
No. of permutations of r objects to n, nPr = n!/(n - r)!
No. of combinations of r objects from n, nCr = n!/(n - r)! r!
Permutations - order matters, combination - order doesn't matter.
0! = 1.

P(X = r) = nCr x q^n-r x p^r.
B(n, p) expectation of no. of successes = np.

Hypothesis testing, check:
1. Test set up before/after data known?
2. Sample chosen at random/independent?
3. Does it test original claim?

Steps for hypothesis testing:
1. Establish null and alternative
2. Decide significance
3. Collect data (random so items independent)
4. Conduct test
5. Interpret result in terms of original claim.

That's about it.

Some resources:
http://learn123.co.nr/ms1.php (my website with video tutorials for MEI)
http://www.mei.org.uk/files/papers/MEI_S1.pdf (all past papers)
http://www.mei.org.uk/files/pdf/formula_book_mf2.pdf (formula book)

thats so helpful

[ss2012]

anyone has the marking scheme for this paper?