AQA S1 May 18

Original post by mrxstardust

two.

Why did we have to times by six? I thought that timsing the three fractions were enough?

Reply 81

Original post by olivia135

how did u do the proving indepenance one???

You know the conditional probability part? Just work the probability out without that condition.

For independent events:

P( B given A has occurred ) = P(B) because they don't influence each other.

Sorry I'm bad at explaining things. :frown:

Reply 82

thedifferentiator

Original post by JulietheCat

You know the conditional probability part? Just work the probability out without that condition.

For independent events:

P( B given A has occurred ) = P(B) because they don't influence each other.

Sorry I'm bad at explaining things. :frown:

It wasnt independant was it?

100% certain that it said show that it was not independant meaning it was dependant.

Reply 83

Original post by JulietheCat

Why did we have to times by six? I thought that timsing the three fractions were enough?

they select three at random, so it can be in any order. The order you used was one of six ways. you times it by 3!(factorial) which is 6.

Reply 84

Original post by thedifferenatiator

It wasnt independant was it?

100% certain that it said show that it was not independant meaning it was dependant.

I meant I showed:

P(B|A) does not equal P(B). Therefore, not independent.

Reply 85

Original post by mrxstardust

they select three at random, so it can be in any order. The order you used was one of six ways. you times it by 3!(factorial) which is 6.

I didn't realise that. And to think that I aced the Solomon Paper L last night! :frown:

Reply 86

speed2001

It said the total of red and purple paperclips, do you just add the probabilities and do binomial distribution of it.

Reply 87

Original post by speed2001

It said the total of red and purple paperclips, do you just add the probabilities and do binomial distribution of it.

yh thats what I did, it seemed obvious lol.

Reply 88

Original post by JulietheCat

I didn't realise that. And to think that I aced the Solomon Paper L last night! :frown:

best thing to do is the boards papers, because i found this paper easy because i have seen most of these questions, and you actually get used to the wording of the questions. There is a limit to what they can ask you so the questions are similar. If you learn all the standard methods and standard comment questions the minimum you can get is a B. ( due to the element of surprise )

Reply 89

speed2001

Original post by mrxstardust

yh thats what I did, it seemed obvious lol.

so what is p = 0.35 n = whatever it was

and i forgot the question but was there a question where you had times a probability by the power 4

Reply 90

Rainingshame

13

Original post by speed2001

It said the total of red and purple paperclips, do you just add the probabilities and do binomial distribution of it.

it was the only way seeing as how the table had to be used(unless you had 30 minutes to kill). 0.22+0.13 =0.35 but neither of the two separately are listed :P

Reply 91

Original post by mrxstardust

best thing to do is the boards papers, because i found this paper easy because i have seen most of these questions, and you actually get used to the wording of the questions. There is a limit to what they can ask you so the questions are similar. If you learn all the standard methods and standard comment questions the minimum you can get is a B. ( due to the element of surprise )

I did both past papers and Solomon papers. Solomon papers benefited me by getting me into the habit by thinking deeper into the problem. At school, we do all past papers anyway and we've done all of them. I found this exam easier than expected as I have done the hardest possible S1 questions.

Plus they prepared me for the worst case scenario. I was expecting linear interpolation on this exam as it is in my textbook and Mymaths but never ever showed up. I'm confused why that is.

I didn't know whether to use x - ns for the bleach question. And when I drew the regression lines, they didn't intersect.

I don't know why I'm stressing though. I've done a mock in school and timed Solomon Press papers and I did well, despite silly mistakes. Sorry for such a long reply...

Reply 92

speed2001

For the probability question, I did C) then B) so on my answer page it goes a) i, ii, iii and then c) THEN b). But i've written the letter in the margin. Do you think ill lose my marks for those two questions?

Reply 93

Original post by speed2001

so what is p = 0.35 n = whatever it was

and i forgot the question but was there a question where you had times a probability by the power 4

yh that was binomial, and that is the correct answer. I think it was to the power of 4.

Reply 94

jckk

Original post by mark17188

Was the probability one defo over 194,193 and 192
If so I only messed up the confidence interval
Lost probably about 6/7 because i didn't see the fact you needed to change the measurement -.-

Probably lost at most 15 then, still be okay to get my A as long as i get 80+ in c4

got the same as you in probability here over 194, 193, 192 !
and i never changed measurements T_T fml

Reply 95

thedifferentiator