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:S
P.S What is going on with my picture can you change it please
Phoebe,
Q4c: Think about everything that George did – don’t just focus on what Albert said.
Emma Q4b:
Work out the probability of each individual doing well – from the data in the table – then think about how probabilities are combined.
Can you help me with Q4b please Mrs Tibble?
Okay thank you, so i just say like Gerorge 1/2?
for the home work on q 1 what does HCF mean
How do you combine probablties?
don’t worry i found out
hi mrs Tibble
you know what you said about cxombining probabilities to emma, but how would you do that??
and again :s
on page 15 question 3 do you just look at the table and write the result
Holly :S
Hols it is page 18 for d h/w. I thought.
Hey
How do you combine probabilities? Question 4B
Page 18 exercise 3.6
Thanks
Well, take a simple example:
If the probability of getting a 5 on a die is 1/6 and the probability of getting tails on a coin is 1/2 then the probability of getting 5 on a die AND tails on a coin is (1/6) x (1/2)
So to combine probabilities like this you multiply the two probabilities.
OK?
Hi again.
Don’t worry managed to figure it out
Thanks anyway
Thank you Mr B
Hi. On page 17, question 5a, what is experimental probability, and how would you figure it out compared to theoretical probability?
Hi Hannah,
Experimental probability is worked out by doing the experiment lots of times yourself, whereas theoretical probabilities are the values you would expect from the logic of what you are doing or using.
For example, if you throw a dice lots of times – and it isn’t biased(weighted) in any way, then you would expect each number to come up for one sixth of your throws. That’s the theoretical probability. However, if you actually do the experiment yourself, you are unlikely to get exactly that result. Suppose you throw the dice 600 times and 150 of those results are a 2, then the experimental probability of getting a 2 is 150/600 which simplifies to 1/4.
Does that help?
JT
Hi (again)
I am really sorry but is theoretical probability?
Emma,
Your question doesn’t make sense!! Are you asking what theoretical probability actually is?
It’s the probability you would expect from the nature of your experiment, assuming everything is fair and all results are equally likely. eg if you are tossing a coin, you can get heads or tails. If these are equally likely, you would expect P(heads) = 0.5 and P(tails) = 0.5. These are the theoretical values. If you toss a coin 10 times, however, you probably won’t get 5 heads and 5 tails. Let’s say you got 7 heads and 3 tails; then your experimental probabilities based on your results would be P(heads) = 7/10 and P(tails) = 3/10.
Does that help?
JT
I understand now, but I was wondering what is was like how you find/define it. But thanks for the help anyway
Hi Emma,
Definition could be:
It’s the probability you would expect from the nature of your experiment, assuming everything is fair and all results are equally likely.
So you would count all the outcomes that are possible for whatever you are doing, and then assume that all these outcomes are equally likely to happen. Working out your probability in this way is the theoretical value.
Actually doing an experiment yourself and working out the probabilities from the results you got is how you find experimental probability.
JT
What were the questions for page 21 ?
Question 5
Hols
Im stuck on question 6 on page 20 though :s
i don’t under stand q 3 on p21
Is it ques 3 and what else? Holly, you just have to take their lose from their original weight. It’s in our notebooks
for q 6 you just do the fractions first and then do the bigger numbers
did we have to do question 3?
on page 20 it 5 and 6 on page 21 its 3
Oh,thanks Emma
can any one help me on q 3 on p21
Basically you just have to do like this,
15/1 x 2/5 ( and times it normally )
i really don’t get it
Hi
on question 2 page 23 does it says use a mental method do we still have to show our workings or not. Thanks
Hi Ellie,
If they are easy, just write down the answer as it will be obvious what you have done. If there’s more than one step, write each one down, but all the calculating is done in your head.
JT
thanks
Heyy
I’m really stuck on question 5 on page 65. D’you have to calculate the prices first? :S
Hi
I am stuck on question 5 page 65 exercise 11.2
Thanks.
Hi
I am stuck on question 5 page 65 exercise 11.2
Thanks.
:S
sorry didn’t mean to send that twice
Holly and Ellie, I don’t have a book here. Can you tell me what the question is asking you to find?
Yes.
It is question 5 a and it says:
Five friends each buy a scientific calculator. These are the prices that the paid:
£8.45, £5.50, £5.25, £6.95, £5.25
a) David wants to know if his calculator cost more than most of the others. Which average should he use? What is the value of this average?
But it doesn’t say what David had to pay so therefor I don’t know how to work out of the average!
Thanks
Hi Ellie,
You don’t need the cost of David’s to average the others. You just need to decide if he would be better comparing his with the mean or median, and then work that out for the 5.
Good luck
JT
Ok Thank you!!!
What are homework questions? was it 2 and 6 or 2 to 6?
Emma, go for 2-6 then you’re safe!!
JT
No! Do 2 AND 6 only please.
Mr B to the rescue Emma