What does the confidence interval mean for a two-sample t-test?

What does the confidence interval mean for a two-sample t-test?

The confidence interval provides a range of likely values for the difference between two population means. For example, a 95% confidence level indicates that if you take 100 random samples from the population, you could expect approximately 95 of the samples to produce intervals that contain the population difference.

How do you interpret a 95% confidence interval for a 2 sample t-test?

If a 95% confidence interval includes the null value, then there is no statistically meaningful or statistically significant difference between the groups. If the confidence interval does not include the null value, then we conclude that there is a statistically significant difference between the groups.

How do you interpret t-test confidence intervals?

A normal 95% CI for a difference of means = 0.25 would be something smaller like 0.20 to 0.30 where you could say if my difference of means is 0.25 then the true mean is probably somewhere between 0.20 and 0.30. Your test shows true mean between 0.02 to 0.48 which is a huge range.

How do you know if a confidence interval is statistically significant?

If the confidence interval does not contain the null hypothesis value, the results are statistically significant. If the P value is less than alpha, the confidence interval will not contain the null hypothesis value.

What is a 2 sample t interval used for?

Two sample t intervals are a specific type of confidence intervals that are used to depict the range of difference in the mean values of two groups. These two groups are independent or different. The aim is to find out whether the difference in the means of these two groups is significant or not.

How do you compare two confidence intervals?

To determine whether the difference between two means is statistically significant, analysts often compare the confidence intervals for those groups. If those intervals overlap, they conclude that the difference between groups is not statistically significant. If there is no overlap, the difference is significant.

How do you read a one-sample t-test?

How to Do a One Sample T Test and Interpret the Result in SPSS

1. Analyze -> Compare Means -> One-Sample T Test.
2. Drag and drop the variable you want to test against the population mean into the Test Variable(s) box.
3. Specify your population mean in the Test Value box.
4. Click OK.
5. Your result will appear in the SPSS output viewer.