Statistics How To

Critical Values > Critical Chi-Square Value Critical Chi-Square Value: Overview Read on below if you want to skip to finding the critical chi-square value. The chi-square statistic is used to compare two categorical variables to see if they are related. Calculating the statistic involves looking the figure up in the chi-square table. The chi-square table … Read more

Probability Distributions > Rayleigh distribution What is the Rayleigh distribution? The Rayleigh distribution is a continuous probability distribution for non-negative-valued random variables — variables of 0 or higher. It is skewed right, with its maximum point occurring at a non-zero point. The distribution is used to model the magnitude of random variables that show circular … Read more

TI 83 > TI 83 NormalCDF TI 83 NormalCDF / TI 84: Overview The TI 83 and TI 84 graphing calculators can help you figure out normal distribution probabilities with the normalcdf function. Normalcdf is the normal (Gaussian) cumulative distribution function on the TI 83/TI 84 calculator. If a random variable is normally distributed, you … Read more

TI 89 for Statistics > Binomial Probability TI 89 Binomial Probability TI 89 Overview The TI-89 Titanium graphing calculator is a powerful, hand held calculator that can plot graphs, make bar graphs, and calculate just about anything related to probability and statistics. It’s possible to calculate binomial probabilities by hand, the TI-89 graphing calculator will … Read more

TI 89 for Statistics > TI 89 Hypothesis Testing TI 89 Hypothesis Testing Overview The TI 89 takes away the tedium of the calculations, allowing you to concentrate on the meaning of the testing. You will usually be working on your alternate hypothesis. For example, you think that average weights have gone up or down … Read more

TI 83 > Critical z value TI 83 Critical z value TI 83 A critical value in a hypothesis test separates the rejection region (where the hypothesis will be rejected) from the region where the hypothesis will not be rejected. You could use the equation above to find the z-score; with a little arithmetic, you … Read more

Statistics Definitions > Continuity Correction Factor What is the Continuity Correction Factor? A continuity correction factor is used when you use a continuous probability distribution to approximate a discrete probability distribution. For example, when you want to use the normal to approximate a binomial. Watch the video for an example: According to the Central Limit … Read more

TI 89 > How to find linear regression on ti-89 Contents: TI-89 Regression (Linear). TI-89 Regression (Trigonometric). TI-89 Regression (Exponential) (Opens in new window). Quadratic Regression (Opens in new window). 1. How to find linear regression on TI-89: Steps Example problem: Find a linear regression equation (of the form y = ax + b) for … Read more

Probability > How to Use a Probability Tree Probability trees are useful for calculating combined probabilities for sequences of events. It helps you to map out the probabilities of many possibilities graphically, without the use of complicated probability formulas. Why Use a probability tree? Sometimes you don’t know whether to multiply or add probabilities. A … Read more

Probability > Probability of a Random Event What is a Random Event? A random event is something unpredictable. As it is unpredictable, you can never give it an exact value / probability. For example, you couldn’t predict the probability of falling down a flight of stairs in the next ten years, as that’s a completely … Read more