x
Solved

# Data statistical significance with confidence factor

Posted on 2014-01-17
Medium Priority
205 Views
Hi,

With a supplied set of data say...

0.2 1.4 3.2 2.2 6.4 3.1 9.2 5.3 3.3 2.9 etc

How can I calculate the statistical significance of this data and show the confidence level in %, and also if I wish it to be defined i.e. I want 95% confidence, how do I get it to inform me of the number of samples required to achieve this level?

Thank you
0
Question by:DemonForce
• 2

LVL 24

Expert Comment

ID: 39790558
For confidence levels you require more information than simply a list of numbers.

0

LVL 43

Assisted Solution

Rob earned 1000 total points
ID: 39791310
0

Author Comment

ID: 39826361
Ok, if I want 95% and I keep entering in numbers between 0.0 and 999.9, using mathematical techniques I need to know as I continue to type numbers in what the current confidence factor is, and how many more samples I need to keep inputting to get this to 95%
0

LVL 24

Accepted Solution

Steve earned 1000 total points
ID: 39827416
But confident of what?
With these numbers between 0 and 1000 you want to 95% confident they are ... ?

You can determine the average of the numbers. "xBar"
You can determine the standard deviation of the numbers. "sigma"
you can then multiply the standard deviation by 1.96. "1.96sigma"
Then xBar - 1.96sigma = lower confidence interval at 95%
Then xBar + 1.96sigma = upper confidence interval at 95%
Therefore you could say that with the data there is a 95% chance numbers will fall between the upper and lower confidence levels (in a continuous process the likelihood is 95% that the next number will be between these numbers.

But to get to a practical confidence factor you would need to have a target for the upper and lower... such as "I want to be 95% confident that the numbers are between 250 and 750".

ATB
Steve.
0

## Featured Post

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.