# Maths!!!

Watch
Announcements
This discussion is closed.
Thread starter 16 years ago
#1
Hi!
You no histograms in maths. Well I was just wondering wot u wud use them 2 show?????? PLEASE PLEASE PLEASE help, I really need 2 no!!!
THANX!
0
16 years ago
#2
(Original post by CHAD)
Hi!
You no histograms in maths. Well I was just wondering wot u wud use them 2 show?????? PLEASE PLEASE PLEASE help, I really need 2 no!!!
THANX!
the um size of various groups of seperate data.
0
16 years ago
#3
(Original post by ]{ingnik)
the um size of various groups of seperate data.
anything relating to frequency

how many people could do a task in 1minute, 2-3minutes, 4-5minutes, 6minutes and over etc..
0
Thread starter 16 years ago
#4
(Original post by byb3)
anything relating to frequency

how many people could do a task in 1minute, 2-3minutes, 4-5minutes, 6minutes and over etc..

Do you know how I would use one if I wanted to represent the BMI's of boys in year 7?
0
16 years ago
#5
(Original post by byb3)
anything relating to frequency

how many people could do a task in 1minute, 2-3minutes, 4-5minutes, 6minutes and over etc..
Yes, that's a good explanation.

As long as you know how to answer exam questions on Histograms, then that is fine.
0
16 years ago
#6
(Original post by bono)
Yes, that's a good explanation.

As long as you know how to answer exam questions on Histograms, then that is fine.
i hate pigging histograms, with their frequency density and class width intervals and such.
0
16 years ago
#7
(Original post by CHAD)
Do you know how I would use one if I wanted to represent the BMI's of boys in year 7?
well seperate the BMI into sensible groups (depends on how much data you have). Then count how many boys fall into each group.
0
16 years ago
#8
(Original post by ]{ingnik)
i hate pigging histograms, with their frequency density and class width intervals and such.
Yes I know, that is why i am doing Mechanics instead of Stats for my Maths A-Level!

(Although when I start Further Maths in June, I'll be doing some Stats modules anyway).
0
Thread starter 16 years ago
#9
(Original post by byb3)
well seperate the BMI into sensible groups (depends on how much data you have). Then count how many boys fall into each group.

Cool thanx! so say i seperate it into 3 groups of 2 so
19-21, 4 boys
21-23, 5 boys
23-25, 7 boys
and draw the histogram.
What kinda thing wud i say about it?
0
16 years ago
#10
(Original post by CHAD)
Cool thanx! so say i seperate it into 3 groups of 2 so
19-21, 4 boys
21-23, 5 boys
23-25, 7 boys
and draw the histogram.
What kinda thing wud i say about it?
that it is negatively skewed (look it up if you don't know what it means).
0
16 years ago
#11
I bet ur doing that MAyfield coursework - I'm doing that too... do you know how to draw proper histograms in Excel with unequal class intervals?
0
Thread starter 16 years ago
#12
(Original post by me!)
I bet ur doing that MAyfield coursework - I'm doing that too... do you know how to draw proper histograms in Excel with unequal class intervals?

The problem is I have lost all my notes on histograms. Sorry if im bugging ne1, but cw is in 4 2moro and i need it desperately. Yeah, mayfield high cw, unequal class intervals?
0
16 years ago
#13
(Original post by CHAD)
The problem is I have lost all my notes on histograms. Sorry if im bugging ne1, but cw is in 4 2moro and i need it desperately. Yeah, mayfield high cw, unequal class intervals?
In a histogram the area of the bar is proportional to the frequency of each class, so on the y axis you have frequency density or the relaitve frequency... I can't get excel to do this... BTW negaitively skewed means that most of the values are high... I think you have to draw the shape of distribution to get the best marks...
0
Thread starter 16 years ago
#14
(Original post by me!)
In a histogram the area of the bar is proportional to the frequency of each class, so on the y axis you have frequency density or the relaitve frequency... I can't get excel to do this... BTW negaitively skewed means that most of the values are high... I think you have to draw the shape of distribution to get the best marks...

hi
thank u sooooo much! frequency density is just the number of people in the classinterval but it is show in area instead of the other way? is the right?
thanks soooo much!!!!!!
0
16 years ago
#15
(Original post by CHAD)
hi
thank u sooooo much! frequency density is just the number of people in the classinterval but it is show in area instead of the other way? is the right?
thanks soooo much!!!!!!
Yep… so to work out the height that the bar goes up the y axis you do the frequency divided by the class width, because then when you draw the graph the area of the bar will give you the frequency. For example if a class interval was 0 – 8 with a frequency of 2, the width of the class would be 8, so to get the height of the bar on your histogram you would divide 2 (the frequency) by 8 (the class width), this would give you 0.25, so your bar on the histogram would be 0.25 high. This 0.25 is the frequency density, so if you multiply this frequency density by the class width it gives you the frequency … hope that makes sense.
0
Thread starter 16 years ago
#16
(Original post by me!)
Yep… so to work out the height that the bar goes up the y axis you do the frequency divided by the class width, because then when you draw the graph the area of the bar will give you the frequency. For example if a class interval was 0 – 8 with a frequency of 2, the width of the class would be 8, so to get the height of the bar on your histogram you would divide 2 (the frequency) by 8 (the class width), this would give you 0.25, so your bar on the histogram would be 0.25 high. This 0.25 is the frequency density, so if you multiply this frequency density by the class width it gives you the frequency … hope that makes sense.

ahhhh thanks soooo much!!!!!! if u ever want help ask! bearing in mind i may not no, but u no ill try! THANKS!
0
16 years ago
#17
(Original post by CHAD)
ahhhh thanks soooo much!!!!!! if u ever want help ask! bearing in mind i may not no, but u no ill try! THANKS!
Hey ur welcome
0
16 years ago
#18
Does anyone know how to draw proper histograms in Excel - it won't let me do proper unequal class intervals...
0
X
new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### What are you most likely to do if you don't get the grades you were expecting?

Go through Clearing (230)
39.18%
Take autumn exams (174)
29.64%
Look for a job (20)
3.41%
Consider an apprenticeship (23)
3.92%
Take a year out (105)
17.89%
Something else (let us know in the thread!) (35)
5.96%

View All
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.