# Standard Deviation Curve

Discussion in 'Microsoft Excel Misc' started by rai_lanc@hotmail.com, Sep 13, 2007.

1. ### Guest

To all who can help,

I work for a company who deals with customer dwell time between areas
of a shopping centre.
They are tracking people between 2 points to see how long they are
spending in a particular area.

I can run reports myself, but using a Java Based program that
interrogates a database of customers, and where they have been.

Anyway, the information I get is this :

Sample Count : 727
Mean Dwell Time in minutes : 9.6818
Standard Deviation : 22.9481

I also can see a standard deviation curve on the screen, but I can't
export this to Excel...

My problem is, that I already KNOW the Standard Deviation and the Mean
Dwell Time, but I want to re-produce these curves in Excel.

I can't see a way of plotting a curve when I already know the Standard
Deviation.
I'm new to this, and I'm probably missing something somewhere - I just
don't know what!!!

Any help would be greatly appreciated,

Many thanks,

Rachael

, Sep 13, 2007

2. ### GuestGuest

just did Google search for Dwell time curve and saw a lot of options.
--
HTH,
Barb Reinhardt

"" wrote:

> To all who can help,
>
> I work for a company who deals with customer dwell time between areas
> of a shopping centre.
> They are tracking people between 2 points to see how long they are
> spending in a particular area.
>
> I can run reports myself, but using a Java Based program that
> interrogates a database of customers, and where they have been.
>
> Anyway, the information I get is this :
>
> Sample Count : 727
> Mean Dwell Time in minutes : 9.6818
> Standard Deviation : 22.9481
>
> I also can see a standard deviation curve on the screen, but I can't
> export this to Excel...
>
> My problem is, that I already KNOW the Standard Deviation and the Mean
> Dwell Time, but I want to re-produce these curves in Excel.
>
> I can't see a way of plotting a curve when I already know the Standard
> Deviation.
> I'm new to this, and I'm probably missing something somewhere - I just
> don't know what!!!
>
> Any help would be greatly appreciated,
>
> Many thanks,
>
> Rachael
>
>

Guest, Sep 13, 2007

3. ### James SilvertonGuest

wrote on Thu, 13 Sep 2007
02:26:51 -0700:

rl> I work for a company who deals with customer dwell time
rl> between areas of a shopping centre.
rl> They are tracking people between 2 points to see how long
rl> they are spending in a particular area.

rl> I can run reports myself, but using a Java Based program
rl> that interrogates a database of customers, and where they
rl> have been.

rl> Anyway, the information I get is this :

rl> Sample Count : 727
rl> Mean Dwell Time in minutes : 9.6818
rl> Standard Deviation : 22.9481

rl> I also can see a standard deviation curve on the screen,
rl> but I can't export this to Excel...

rl> My problem is, that I already KNOW the Standard Deviation
rl> and the Mean Dwell Time, but I want to re-produce these
rl> curves in Excel.

If you know a mean and standard deviation, any of the several
methods for producing a normal error curve might do what you
want.....even NORMSDIST tho' it's not my favorite method.
I personally prefer

SQRT(LN(RAND())*(-2))*COS(RAND()*2*PI()) *sigma + mean

James Silverton
Potomac, Maryland

E-mail, with obvious alterations:
not.jim.silverton.at.verizon.not

James Silverton, Sep 13, 2007