Official Exam 2 Discussion

[hanhanchampion]

also, could anyone explain 1 a iii  in a more algebrac way?? i got the answer same as ii though.....

Mean = integral over [2,6] of xf(x)dx, enter into calculator => 4.1333 hours

is that question 1 a iii?  i think it's the last question of 1......  i got that though...

Sorry:

What is the probability, correct to three decimal places, that her first 4 attempts at scoring a goal are successful, given that exactly 6 of her first 8 attempts at scoring a goal in a match are successful?

Combinatorics solution:

• Given exactly 6 successes == given exactly 2 failures
• Our probability space has these 2 failures anywhere in the 8 attempts, so 8 choices for the first fail * 7 choices for the second fail = 56
• The event we want has these 2 failures anywhere in the last 4 attempts, so 4 choices for the first fail * 3 choices for the second fail = 12
• 
  

Yes, I saw that, i just don't understand...  it seems to be explaining a lot..

She shoots for goal 8 times;

Split the problem into two scenarios: the first four shots at goal[1], then the next four[2].

[1] Probability she scores each of the first four times
n=4, r=4, p=0.8 => Pr(X=4) = (4C4)(0.^4(0.2)^0 = 0.8^4 = 0.4096

[2] Probability she scores two of the next four times
n=4, r=2, p=0.8 => Pr(X=2) = (4C2)(0.^2(0.2)^2 = 0.1536

[1] x [2] = 0.063 to 3 d.p.

From part a)ii) of that question, Pr(X=6) = 0.2936

Conditional probability: 0.063 / 0.2936 = 0.214 to 3 d.p.

sign.. i wish i knew how to do it during the exam..
well, thanks synesthetic

[username]

Do you guys all reckon that the cut off for this exam will be similar if not exactly the same to 07?

[equinox]

lol what'd you have to do for that question where you had to find the probability that the chick's first 4 shots were succesfull given that she got 6 out of 8 shots?

That muddled me up so bad

I don't remember this. I only remember that "what was the probability that exactly six shots out of eight were successful?"

Yes thats what I remember aswell. Do u do CAS by any chance?

[sandhya]

hey what study score can i expect with approx 78/80 and 39-40/40?

[BrooklynZoo]

GET DA CALCULATIONS HILAVIN MAGRAVIN MAINFRAME SYTAX CALCULATORZ
its over...school is for suckers

[sandhya]

hey im such a retard, i messed up the domains of the normal and the end graph (tangent/sine function). do you reckon im going to be penalised twice?

[We Want Peace.]

hey what study score can i expect with approx 78/80 and 39-40/40?

definitely  48 +.
Probably a 50.

[sandhya]

oh shit, you for real? *goes an dies with happiness*

[We Want Peace.]

oh shit, you for real? *goes an dies with happiness*

your scores are pretty good.
nearly 100%
Plus i expect this yr's cutoff would be similar as last year.(07')
so yeah...u will be good enough to get a A+ and 48+  if ur sac ranking is high as well.

[shuun]

HAHAHa i made a bet with a friend that there will be a Tasmania Jones question. Woot 10 bux to me!

[Mikey123]

What marks exam 1 and exam 2 do you reckon you need for a 25 raw?

[sandhya]

oh shit, you for real? *goes an dies with happiness*

your scores are pretty good.
nearly 100%
Plus i expect this yr's cutoff would be similar as last year.(07')
so yeah...u will be good enough to get a A+ and 48+  if ur sac ranking is high as well.

hey - sacs i have 97/100, ranked third. i want to know, do you think id be penalised twice for messing up the domain when sketching graphs? it was one of those 'i am so dumb' moments, whoever heard of messing up a domain that is pretty unrestricted?

[sam2703]

hey guys, yeh silly mistakes smashed me aswell, say 38/40 and 75/80, with high a+ sacs at mhs
what ss u think i can get

[sandhya]

hey sam 2703 - not TOO sure, but probably 44+:)

[sam2703]

sweet as 44 or above and im more than happy, by the way i doubt ud get penalised twice  for the same mistake