# Confidence Intervals

1. Jan 28, 2006

### blumfeld0

Hello. I am teaching myself statistics and my question is about confidence intervals. I understand that I can accept or reject a null hypothesis based on comparing my p values to the significance value (say .05)
But how do i accept or reject a null hypothesis based SOLELY on
a given confidence intervals say -12 to 1.4?
thanks

blumfeld0

2. Jan 28, 2006

### ksinclair13

Say you have a confidence interval of 99% confidence, and the range is (-12, 1.4). If you have a number that lies outside of that range (let's say 1.9), then you can reject $H_0$ (and accept $H_a$) at $\alpha = .01$. If the number does lie inside that range (let's say -3), then you accept $H_0$ (and reject $H_a$).

Last edited: Jan 28, 2006
3. Jan 28, 2006

### blumfeld0

Hi. Thanks for your reply. That is the problem. A colleaugue of mine told me that you can accept or reject the null hypothesis solely given the confidence interval without being given the actual data or significance level (99%, 95%)
Is he right?
if so how?
thanks

blumfeld0

4. Jan 30, 2006

### xorbie

a confidence level always has a significance level associated with it, so no.

5. Feb 4, 2006

### EnumaElish

Confidence level = 1 - significance level