Project Maths Sample Paper: Probabilty

shaunie007

Hi folks,

I was wondering if anyone can do the following question for me:

http://www.examinations.ie/schools/Project_Maths_Phase_2_P2_Ordinary_Level.pdf

Question 2 about the biased die: a and b if you can.

Cheers

Anonymo

shaunie007 wrote: »

Hi folks,

I was wondering if anyone can do the following question for me:

http://www.examinations.ie/schools/Project_Maths_Phase_2_P2_Ordinary_Level.pdf

Question 2 about the biased die: a and b if you can.

Cheers

I think most people on boards would have no problem trying to help someone out in doing a question. A lot of people here are pretty helpful in such a case. However, to ask someone to do your homework is fairly cheeky! To HELP you out I'll do a similar type of question for you... For part (a) remember expectation value is the same as the (long-term) average of running this experiment may times. So suppose you've a case where you toss a biased coin with
prob(tails)=0.2, prob(heads)=0.8. A heads in our game will correspond to a 2, while a heads will correspond to a 1. The expected value will be
2*0.8+1*0.2=1.8
[Aside: A way of thinking of this is that on average 2 times out of 10 you'll get a tails (a 1) and 8 times out of 10 you get a heads (a 2). If you sum up the total of the '10 experiments' and get the average you find (2*1+8*2)/10=1.8]

Q2.(a) is similar to this.

For Q2(b) the average you'll earn with a fair die is the average number you get when you throw a die minus the 3 euro it costs to play the game.
For the other part you take the answer to part a which tells you the average of throwing the biased die many times and then subtract a 3 e.g.
if your answer to 2(a) was 2.50 (it's not - this is an example!) then 2.50-3.00=-0.50,i.e. you would lose 0.50 euro on average per game (again this is NOT the answer).

shaunie007

Anonymo wrote: »

I think most people on boards would have no problem trying to help someone out in doing a question. A lot of people here are pretty helpful in such a case. However, to ask someone to do your homework is fairly cheeky! To HELP you out I'll do a similar type of question for you... For part (a) remember expectation value is the same as the (long-term) average of running this experiment may times. So suppose you've a case where you toss a biased coin with
prob(tails)=0.2, prob(heads)=0.8. A heads in our game will correspond to a 2, while a heads will correspond to a 1. The expected value will be
2*0.8+1*0.2=1.8
[Aside: A way of thinking of this is that on average 2 times out of 10 you'll get a tails (a 1) and 8 times out of 10 you get a heads (a 2). If you sum up the total of the '10 experiments' and get the average you find (2*1+8*2)/10=1.8]

Q2.(a) is similar to this.

For Q2(b) the average you'll earn with a fair die is the average number you get when you throw a die minus the 3 euro it costs to play the game.
For the other part you take the answer to part a which tells you the average of throwing the biased die many times and then subtract a 3 e.g.
if your answer to 2(a) was 2.50 (it's not - this is an example!) then 2.50-3.00=-0.50,i.e. you would lose 0.50 euro on average per game (again this is NOT the answer).

Cheers