Generating A Skewed Normal Distribution Of Random Numbers |
Generating A Skewed Normal Distribution Of Random Numbers - Excel |
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I need to randomly generate a set of 5000 numbers using just the following three inputs:
>Min
>Mean
>Max
They have to be normally distributed, but as the mean is never exactly half way between the min and max, the distribution will be skewed.
I am using =(NORMSINV(RAND())*0.13)+0.5 to give me 5000 random numbers that are normally distributed with a mean of 0.5 and (almost always) have a min of 0 and a max of 1.
I am then mapping these to the distribution that I require using
If random number < 0.5, f(x)=min+2*rand*(mean-min)
If random number = 0.5, f(x)=mean
If random number > 0.5, f(x)=mean+2*(rand-0.5)*(max-mean)
As expected this is giving me numbers within the predefined bounds, however the mean is way off what I was expecting.
For example, a min of 50,000, mean of 225,000 and a max of 1,000,000 give the following output:
>Min ~ 50,000-60,000 (this is close enough)
>Mean ~ 288,000-290,000 (this is no where near)
>Max ~ 950,000-1,000,000 (this is close enough)
I am not sure if there is a problem with my mapping formula, if it is to do with how I am generating the random numbers in the first place, or something else, but I am now stuck.
If anyone has any experience of this, or can offer any advice, then I would be most grateful!
Many thanks in advance,
Graham
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I'd like to do this in Excel, but I can't figure out how to have a randomly generating non-repeating macro with text values in cells.
So right now I have a column of 8 values and need matrix of 7 columns by 8 rows next to it.
I've found this thread that has one for numbers, but I can't figure out how to do it for text values...
http://www.excelforum.com/excel-prog...m-numbers.html
Thanks all!
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Hoping someone can help me quickly as I'm pulling my hair out and have a deadline getting too close.
Been trailing the net and this board but can't work out how to do a simple variance.
How do I work out the difference between two numbers - including negatives.
If the numbers are all positive, it's fine as it's simply a case of A - B = C which is your difference. However, that doesn't work if B is negative.
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lets suppose my numbers a 1,2,3,4,5,6,7,8,9,10,11
I want to generate all possibilities of the 6 numbers. But i dont want duplicate series.. I mean 1,2,3,4,5,6 and 6,5,4,3,2,1 are duplicates.
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I am working with an Excel spreadsheet and saving it as a .csv file in order to upload to an application that parses out the .csv data as transactions. The system requires .csv files, so this is how I need to save my doc (with this extension). I have been successful at preventing Excel from coverting that long number into scientific format. I have saved as a TXT file, pasted the longer number and it displays correctly. That is all good. But I have to save as a .csv. So if I do that, close the Excel window, and then open again (as the .csv file), the numbers are back to being displayed in scientific format. I have tried creating an Excel doc from scratch and entering text in Text format, to see if this created a cleaner file. But again, the second I save as .csv, close the window and then open that file up again, that dang scientific format is back.
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a set of given numjbers. For example, 1, 3 and 8 would generate 138, 183,
318, 381, 813, 831 and so on...
so I thought I would try again.
Does anyone know of an Excel template--or a small stand-alone
program--that will calculate the interest/principal breakdown when
payments are varied in amount and frequency? Free or low-cost, please.
I need one that will work on my Mac/Office 2004. I will need to print
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Here is the way the previous poster described it:
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figures days
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I have a loan with a variable beginning balance and irregular payments
with
annual large payment. (based on collections)
Would like to enter payment and date.
then Excel would figure days since last payment, interest amount,
principal
amount, Ending Principal balance.
And total interest paid, total pricipal paid
If I change the starting principal, excel would recalculate all
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In other words, if I give the following numbers 1, 2, 2, 3, 3, 4, 5, 5, 6, 7, 7 - I want Excel to figure all the possible combinations that will add up to 23, and also SHOW ME those combinations, and not just HOW MANY combinations there are.
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Can this be done? What is the formula? I'm having a hard time figuring it out!!
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For example my numbers are formatted like this: 1234 and I would like to add zeros to the end so it looks like this: 123400 (no decimal).
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Thanks for your help, you guys are great!
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2
3
4
5
6
7
8
9
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3+9
4+8
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Is there a function in Excel that will do this for me? I want to know which numbers (i.e. cells) can be added to reach 12. AND, if possible, colorcode the cells added for each combination.
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I'm a bit of a newbie with Excel, but...
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