ATAR Notes: Forum

VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: dinosaur93 on October 20, 2011, 05:51:15 pm

Title: PROBABILITY
Post by: dinosaur93 on October 20, 2011, 05:51:15 pm

There are 500 cakes, the probability of a cake being overweight is 0.56791.
How many cakes are overweight then?

Pr (Overweight) = 500 x 0.56791 = 283.995


The answer would definitely NOT be 283.995 because that is the expected outcome of overweight cake.

What should the exact answer be then?

Is it 283 or 284 cakes?

Title: Re: PROBABILITY
Post by: monkeywantsabanana on October 20, 2011, 06:12:46 pm

I would say 283 because you haven't reached the 284th cake yet.

Correct me if I'm wrong.

Title: Re: PROBABILITY
Post by: yawho on October 20, 2011, 06:43:51 pm

283.995
incorrect question!

Title: Re: PROBABILITY
Post by: dinosaur93 on October 21, 2011, 10:26:48 pm

Really?! Why so?

How come the question is incorrect?

Please elaborate further to strengthen the argument, tnx

Title: Re: PROBABILITY
Post by: yawho on October 22, 2011, 12:17:06 am

If 283, the prob of getting an overweight cake is 0.566, NOT 0.56791
If 284, the prob of getting an overweight cake is 0.568, NOT 0.56791

Title: Re: PROBABILITY
Post by: yawho on October 22, 2011, 12:26:54 am

If there are 500 ready made cakes, there must be a definite number of overweight cakes, the prob of a cake out of the 500 is overweight can never be 0.56791

Title: Re: PROBABILITY
Post by: RossiJ on October 22, 2011, 11:30:53 am

wha?

I'm interested to know the answer too, if you get an outcome such as 13.89 cakes overweight for example, does it round up or down? some answers I've seen round up, down and stay the same..

what's the best option?

Title: Re: PROBABILITY
Post by: dinosaur93 on October 22, 2011, 01:01:29 pm

to be honest yawho...

I haven't thought of that argument as well...

V. interesting...

So what you're saying is the probability should not equate to an answer that has decimal places, and should rather be an exact whole number?

Title: Re: PROBABILITY
Post by: yawho on October 22, 2011, 03:25:18 pm

I am saying the question is a wrong question to ask.

Title: Re: PROBABILITY
Post by: dinosaur93 on October 23, 2011, 08:23:42 am

What if I change the scenario from cakes to pupils or something like that..

Will it change or still stay the same?

Title: Re: PROBABILITY
Post by: yawho on October 23, 2011, 03:24:48 pm

same