Statistics How To

Probability and Statistics > Microsoft Excel for Statistics > Cumulative Frequency Table in Excel In order to follow this article, you should know how to create a regular distribution table/histogram in Excel. Don’t know how? Check out this video/article first: How to Make a Frequency Distribution Table in Excel. How to Make a Cumulative Frequency … Read more

Probability and Statistics > Basic Statistics > Regression to the Mean Regression to the mean is all about how data evens out. It basically states that if a variable is extreme the first time you measure it, it will be closer to the average the next time you measure it. In technical terms, it describes … Read more

Probability and Statistics > Probability Index > Probability problems Probability Problems Overview. If you’re taking a class in basic probability, right now you’re probably feeling utterly confused with the rules of probability. After all, there are lots. When do add? When to multiply? When to use combinations? Ugh. I remember when I was learning probability … Read more

Statistics Definitions > Friedman’s Test What is Friedman’s Test? Friedman’s test is a non-parametric test for finding differences in treatments across multiple attempts. Nonparametric means the test doesn’t assume your data comes from a particular distribution (like the normal distribution). Basically, it’s used in place of the ANOVA test when you don’t know the distribution … Read more

Probability and Statistics > TI-83 Calculator > Satterthwaite Formula What is the Satterthwaite Formula for Degrees of Freedom?? The Satterthwaite approximation is a formula used in a two-sample t-test for degrees of freedom. It’s used to estimate an “effective degrees of freedom” for a probability distribution formed from several independent normal distributions where only estimates … Read more

Statistics Definitions > Levene Test Contents: What is the Levene Test? Run a Levene’s Test for Equality of Variances in SPSS What is the Levene Test? Levene’s test is used to check that variances are equal for all samples when your data comes from a non normal distribution. You can use Levene’s test to check … Read more

Probability and Statistics > Regression Analysis > Assumptions and Conditions for Regression Assumptions and Conditions for Regression. Regression can be a very useful tool for finding patterns in data sets. However, your data can’t always be fit to a regression line. Most software, like SPSS and Excel, will always give you a the best regression … Read more

Statistics Definitions > Conditional Distribution You may want to read this article first, as it introduces marginal and conditional distributions: What is a Marginal Distribution? What is a Conditional Distribution? A conditional distribution is a probability distribution for a sub-population. In other words, it shows the probability that a randomly selected item in a sub-population … Read more

Probability and Statistics > Probability > Normal Probability Practice Problems These normal probability practice problems will help you practice calculating z-scores and using the z-table. General steps for solving normal probability practice problems: Use the equation above to find a z-score. If you don’t know how to look up z-scores (or if you want more … Read more

Probability Distributions > Open Ended Distribution What is an Open Ended Distribution? An open ended distribution means that one or more of your classes (or bins) is open-ended. In other words, it doesn’t have a boundary. In this frequency distribution table, a height of 57″ or less (in the first row) means this is an … Read more