maths help

[stamp92]

im doing a gcse maths course can somebody help please thanks

does anybody know an easy way to remember and define the differences between discrete quanitative data and continuous data.

these are the definitions as from a maths website


Discrete data can only take specific numeric values

-eg shoe size, number of brothers, number of cars in a car park

Continuous data can take any numerical value

-eg heigh, mass, length

I just get confused in telling the difference between these two types of data. Some things I find easy to categorize like number of brothers is discrete but I dont understand why for example shoe size is Discrete because it could be 5.1 5.22 who knows. what makes it discrete?

can someone tell me whether "time taken to play a cd" is discrete or continuous.

help appreciated thanks

[Lord Nikon]

Shoe size is discrete because it deals with specific numeric sizes i.e. 1,1.5,2,2.5,3,4,5,6,7,8,9,10 etc, beyond the half sizes there are no other fractional components.

You don't find someone saying "I'm looking for a size 10.62578 in these"

Time taken to play a CD I would say is continuous as each CD can have it's own unique playing time, whether that be 3 minutes 27 seconds, or 68 minutes 32.78 seconds.

[stamp92]

Thanks Lord Nikon :wavey:
Have a :beer: on me

[duncant403]

Originally posted by Lord Nikon
Time taken to play a CD I would say is continuous as each CD can have it's own unique playing time, whether that be 3 minutes 27 seconds, or 68 minutes 32.78 seconds.

You could argue that a CD playing time is discrete as the smallest increment of time is 1/100th of a second, and so you could have 68:25.10 and 68:25.11 but not 68:25.103756865

Duncan

[danielf]

Originally posted by duncant403
You could argue that a CD playing time is discrete as the smallest increment of time is 1/100th of a second, and so you could have 68:25.10 and 68:25.11 but not 68:25.103756865

Duncan

I would diagree. Maybe the display only shows you the hundreds, but there are finer distinctions. I guess you could argue that displayed playing time is discrete when actual playing time is continuous. In a similar way foot size is continuous, but shoe size discrete.

[dr wadd]

Originally posted by danielf
I would diagree. Maybe the display only shows you the hundreds, but there are finer distinctions. I guess you could argue that displayed playing time is discrete when actual playing time is continuous. In a similar way foot size is continuous, but shoe size discrete.

Well, in that case, if you are going to argue about the finer distinctions then we can take it all the way down and argue that time is discrete on the Planck scale. :)

[danielf]

Originally posted by dr wadd
Well, in that case, if you are going to argue about the finer distinctions then we can take it all the way down and argue that time is discrete on the Planck scale. :)

;) Let's put it this way. I think that if you were to tick 'discrete' for time in a multiple choice test, the answer would be wrong. If you were to answer 'discrete on the planck scale' in an oral examination followed by a philosophical debate, you might be given full marks despite the examiner disagreeing, because you clearly grasp the concept of continous/discrete.

[duncant403]

Originally posted by danielf
I would diagree. Maybe the display only shows you the hundreds, but there are finer distinctions. I guess you could argue that displayed playing time is discrete when actual playing time is continuous. In a similar way foot size is continuous, but shoe size discrete.

If you really want to argue, CD is digital and sampled at 44.1kHz and so has to be discrete, as all digital signals are discrete by their natural. A record or cassette on the other hand, bring analogue (ignoring digital cassettes) would be continuous...

[danielf]

Originally posted by duncant403
If you really want to argue, CD is digital and sampled at 44.1kHz and so has to be discrete, as all digital signals are discrete by their natural. A record or cassette on the other hand, bring analogue (ignoring digital cassettes) would be continuous...

I didn't want to argue. I thought I was helping to clarify the difference for the Original Poster as I thought the cd example might be confusing :angel:

And yes, you're obviously right is saying that digital signals are discrete.

[Chris]

I did GCSE maths 14 years ago and never came across anything like this. I'm sure it's a conspiracy to keep teachers in a job and prevent parents helping their kids with homework.

Funny how they can load the syllabus with meaningless techno-jargon, yet they can't teach mental arithmetic any more. :rolleyes:

[Jerrek]

oes anybody know an easy way to remember and define the differences between discrete quanitative data and continuous data.
I've never ever heard of this before, and I'm a math major. Eh.

[ntluser]

Originally posted by stamp92
im doing a gcse maths course can somebody help please thanks

does anybody know an easy way to remember and define the differences between discrete quanitative data and continuous data.

these are the definitions as from a maths website


Discrete data can only take specific numeric values

-eg shoe size, number of brothers, number of cars in a car park

Continuous data can take any numerical value

-eg heigh, mass, length

I just get confused in telling the difference between these two types of data. Some things I find easy to categorize like number of brothers is discrete but I dont understand why for example shoe size is Discrete because it could be 5.1 5.22 who knows. what makes it discrete?

can someone tell me whether "time taken to play a cd" is discrete or continuous.

help appreciated thanks

You may find this helpful for discrete quantitative data.

http://www.ex.ac.uk/cimt/mepres/book7/bk7i18/bk7_18i1.htm

And this may help for continuous data.

http://www.isixsigma.com/dictionary/Continuous_Data-96.htm

Hope this helps.