In descriptive statistics, what does "confidence level" mean?

[Dora Smith]

Here are teh descriptive statistics for one of my columns.

Total Records Collected

Mean 617,416.82
Standard Error 38,027.85
Median 629,507.50
Mode #N/A
Standard Deviation 201,224.45
Sample Variance 40,491,281,082.30
Kurtosis -0.26
Skewness 0.21
Range 829,194.00
Minimum 248,690.00
Maximum 1,077,884.00
Sum 17,287,671.00
Count 28.00
Confidence Level(95.0%) 78,026.70



I thought it would be great to get the confidence interval, but instead it
gives me a "confidence level" that doesn't even make sense, and the manual
does not discuss what the "confidence level" is. Frankly the number is
far too small in relation to the mean and the standard deviation to appear
to make sense.

I want to know the level one can have 95% confidence of achieving. That's
the only confidence level that has any meaning to me. That figure would
have to be a couple of standard deviations above 617,000, it seems to me.
Not, 78,026. Since the SD is 201,000, what does the number 78,026 even
mean?

What exactly is Excel's "confidence level"?

 

[Guest]

Answered in the worksheet.functions newsgroup. Please do not separately post
the same question to multiple groups.

Jerry

 

[Dave Peterson]

Check your other post.

Here are teh descriptive statistics for one of my columns.

Total Records Collected

Mean 617,416.82
Standard Error 38,027.85
Median 629,507.50
Mode #N/A
Standard Deviation 201,224.45
Sample Variance 40,491,281,082.30
Kurtosis -0.26
Skewness 0.21
Range 829,194.00
Minimum 248,690.00
Maximum 1,077,884.00
Sum 17,287,671.00
Count 28.00
Confidence Level(95.0%) 78,026.70

I thought it would be great to get the confidence interval, but instead it
gives me a "confidence level" that doesn't even make sense, and the manual
does not discuss what the "confidence level" is. Frankly the number is
far too small in relation to the mean and the standard deviation to appear
to make sense.

I want to know the level one can have 95% confidence of achieving. That's
the only confidence level that has any meaning to me. That figure would
have to be a couple of standard deviations above 617,000, it seems to me.
Not, 78,026. Since the SD is 201,000, what does the number 78,026 even
mean?

What exactly is Excel's "confidence level"?

--
Yours,
Dora Smith
Austin, TX
(e-mail address removed)

 

[James Silverton]

Hello, Jerry!
You wrote on Sun, 11 Feb 2007 06:14:00 -0800:

JWL> Jerry

,
??>> Dora Smith
??>> Austin, TX
??>> (e-mail address removed)
??>>

Please don't think this is a snide remark but an elementary book
on statistics might be useful for reading and reference. I hope
this has not already been suggested in other postings. Here are
a few from Amazon (I know some of the titles sound condescending
:-


The Complete Idiot's Guide to Statistics (The Complete Idiot's
Guide) by Robert A. Donnelly Jr. (Paperback - May 4, 2004)



Statistics for Dummies by Deborah Rumsey (Paperback - Aug 25,
2003)

Buy new: $19.99



Cartoon Guide to Statistics by Larry Gonick and Woollcott Smith
(Paperback - Feb 25, 1994)

Buy new: $17.95







James Silverton
Potomac, Maryland

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