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#1 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 22:39:47
well i found it in my notes, it does say it works best for symmetrical skew, and this is positive but considering the time i guess im gonna have to go with it and hope it is right!
Better go and print it all off
Thank you so much for all your help 
#2 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 22:36:16
ok well it is in my notes so should be right i hope! thank you for your help!
#3 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 22:27:15
ohh yes ok I have got it but i need just the range not the interquartile range.
could this work to find out range:
mean+ (standard deviation x 3) - mean - (standard deviation x 3)
???
#4 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 22:21:09
ohh yea sorry I wasnt a member last night when I first posted the question.
I got the variance from a complicated formula I found on an example page:
fxx/f - mean x mean
is that right?
#5 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 22:17:37
It cant be because I have to find the range and the interquartile range, I am 99% sure the interquartile range is 185 but really dont know how to find minimum and maximum values with no data 
#6 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 22:10:29
yeah i am why does that mean it is wrong?
#7 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 22:08:54
Hi
I am gonna leave the SIR as 185 because atleast one formula we were given supports it
I just need to find the minimum and maximum numbers so I can work out the range
#8 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 22:07:30
Hi thanks for the links but I do not have a list of data to see what the min and max values are, if I had them I know how to work out the range, I just dont know the formula to work out out min and max without the data, do you know how to do it?
sorry I know you dont have to help me but I need to leave to hand it in in 50 mins and really need to pass or I will have to resit the entire module next year
#9 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 22:01:43
ohh no that definitely isn't right umm i have no idea then
#10 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 21:57:08
um no I dont know how to get it, yes range is difference between max and min values
is it median - Q1 for the minimum and median + Q3 for the maximum? that is only a guess Im really not sure, we do not have a formula for it in our notes!
#11 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 21:49:32
Brilliant thank you!
#12 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 21:41:03
Hi I haven't been given the data all I have is what is above and I have to work out range and SIR based on the information given. The median is 50% of the values though so surely it should be right in the middle of Q1 and Q3. It is my university assignment so I doubt that the figures they have given are wrong because the whole class would fail
I think im gonna stick with (Q3-Q1)/2 and ignore the other formula I have been given as they cannot both be right.
Do you know how I can find the minimum and maximum values so I can find the range?
#13 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 21:33:08
and I have to find out:
range (I have no idea how to find the minimum and maximum with the data I have been given?)
semi interquartile range (not sure because of the above)
weekly total salaries - 248x550
shape of distribution - positively skewed as mean > median
#14 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 21:30:39
yes because it is given to me in the question the data I have been given is:
mean - 550
median - 470
lower quartile - 300
upper quartile - 670
standard deviation - 115
number of employees - 248
So it really doesn't make sense unless I am completely missing something?!
#15 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 21:29:06
oops! thank you! so do you think my sums are correct now for this question? have i done all I can do th show a variety of averagges and measures of dispersion?
Thank you so much for helping
#16 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 21:23:40
O another thing is the median is 470, Q1 is 300 and Q3 is 670 so what i have in my notes:
Q1 and Q3 can be found using the approximate rules
Q1 = Median - SIR
Q3 = Median + SIR
doesn't make sense with the numbers I have!?!
#17 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 21:21:31
for this question I am given Q1(lower quartile) and Q3(upper quartile) - 300 and 670
so the formulas I have in my notes contradict
(Q3-Q1)/2
and
Q1 = Median - SIR
Q3 = Median + SIR
do not both work! Sorry I should have been clearer - not sure which one to use!
#18 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 21:16:55
To get the standard deviation I did the square root of the var?
to get the mean i did total fx/ total frequency - 108,440/196
Is that wrong?
#19 Re: Help Me ! » stats - SIR, min and max values?? » 2010-01-20 21:12:31
Hi thank you, that's what Ive done so now I know it is right however in the notes given in class it says
Q1 = Median - SIR
Q3 = Median + SIR
Using the formula the SIR would be 185 but this doesn't fit with the above formula for both Q1 and Q3?
#20 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 21:05:49
all the information I have been given is above, thank you for trying to help I'm an events students so not very good at statistics!
#21 Re: Help Me ! » Statistics Assignment due in tomorrow please help! » 2010-01-20 20:58:35
Hi
I have done this
Mean 553.0612245 Var 4391.139109
Q1 455 St Dev 66.26567067
Median 480 Semi Interquartile Range 65
Q3 585 Minimum 450
Maximum 799
Range 349
But not sure if it is right?? handing it in in 3 hours! please help
#22 Help Me ! » stats - SIR, min and max values?? » 2010-01-20 20:35:06
- lou_needs_maths_help
- Replies: 24
Hi does anyone know how i can find the minimum and maximum values and the semi interquartile range for this data?
mean - 550
median - 470
lower quartile - 300
upper quartile - 670
standard deviation - 115
number of employees - 248
Thankyou
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