i don't really get histograms,if they give you half the graph but no frequecy density , WHAT DO YOU DO?--help PLEASE......

and what are formulas for median and and lower quartile range?

oh and ..........ANY HELPFUL WEBSITES PLEASE GIVE INCLUDING YOUTUBE CLIPS:)

Posted Sat 9th June, 2012 @ 23:29 by

anonymousEdited by

anonymous on Sat 9th June, 2012 @ 23:30

Histograms:

You would have to work out the frequency density from the table using frequency density= frequency/class width. I remember this formula as **F**rankie **F**rog **d**oes **C**art**w**heels! Click on my name for a video of a worked example!

Medians and Quartiles:

Order all the data you have (only if it is ungrouped)

N is the number of data

Position of the Median in list is (n+1)/2...because the M is the 1/2 way point.

Position of the Lower Quartile is (n+1)/4...because the LQ is 1/2 of the median so 1/4.

Position of the Upper Quartile is 3(n+1)/4....because UQ is the M+LQ so 3/4.

The interquartile range is just the value of UQ (not position) - value of the LQ

(When you work out the normal range you minus the lowest number from the highest number and so it is the same concept)

If you don't really get this , look at the video I have uploaded (but it does explain it a little differently).

Hope this helps!! :)

Answered Sun 10th June, 2012 @ 08:22 by

DillyEdited by

Dilly on Sun 10th June, 2012 @ 08:23

btw shouldn't your formulas be **F**RANKIE **D**OES **F**ROG** C**ART**W**HEELS?:)

Answered Sun 10th June, 2012 @ 10:40 by

anonymous
No I do it from the frequency= frequency density * class width and put it in a triangle.

Sorry about the confusion!

Answered Sun 10th June, 2012 @ 10:49 by

Dilly
wat is the triangle for itt ^^

Answered Sun 10th June, 2012 @ 11:13 by

в
The triangle is:

F

-------

fd cw

Answered Sun 10th June, 2012 @ 11:14 by

Dilly
Thank yuee i revise better with triangles!

Answered Sun 10th June, 2012 @ 11:14 by

в
ohh....thanks,yes i watched the video on your profile,and it the guy sort of rearranged the equation

Answered Sun 10th June, 2012 @ 11:25 by

anonymous
Answered Sun 10th June, 2012 @ 11:35 by

в