sunshinepaster.blogg.se - T test with mean and standard deviation excel

Research Question: Is there a (statistically) significant difference between males and females with respect to math achievement? The problem with this is that as you lower the chance of making a Type I error, you increase the chance of making a Type II error.įail to reject a null hypothesis that is false (with tests of differences this means that you say there was no difference between the groups when there really was one) You can reduce the chance of making a Type I error by setting a smaller alpha level ( p <. If you set your probability (alpha level) at p < 05, then there is a 5% chance that you will make a Type I error. The probability of making a Type I error is the alpha level you choose. Reject a null hypothesis that is really true (with tests of difference this means that you say there was a difference between the groups when there really was not a difference). The t test Excel spreadsheet that I created for our class uses the F-Max.

Note: The F-Max test can be substituted for the Levene test. How do I decide which type of t test to use?

Unequal Variance (Separate-variance t test) df dependents on a formula, but a rough estimate is one less than the smallest group Note: Used when the samples have different numbers of subjects and they have different variances - s1s2 (Levene or F-max tests have p <.

We specify the level of probability (alpha level, level of significance, p) we are willing to accept before we collect data ( p. When we assume a normal distribution exists, we can identify the probability of a particular outcome. With all inferential statistics, we assume the dependent variable fits a normal distribution. It is used to determine whether there is a significant difference between the means of two groups. The t test is one type of inferential statistics. A PowerPoint presentation on t tests has been created for your use.

For this course we will concentrate on t tests, although background information will be provided on ANOVAs and Chi-Square. An introduction to statistics usually covers t tests, ANOVAs, and Chi-Square.