Statistics methods
- How to calculate a linear regression line by hand
Learn the exact step-by-step method to calculate the least squares linear regression line by hand using standard summary statistics.
- How to calculate a correlation coefficient
Learn how to calculate Pearson's correlation coefficient (r) to measure the linear relationship between two continuous variables.
- How to run a chi-square test of independence
Perform a chi-square test of independence to determine if two categorical variables are associated by comparing observed and expected frequencies.
- How to run a one-sample t-test
Learn how to perform a one-sample t-test to compare a sample mean to a hypothesized population mean when standard deviation is unknown.
- How to construct a confidence interval for a mean
Learn the exact procedure to construct a confidence interval for a population mean using the t-distribution or z-distribution.
- How to count outcomes with permutations and combinations
Calculate the total number of possible outcomes using permutations for ordered arrangements and combinations for unordered selections.
- How to use Bayes' theorem
A step-by-step guide to calculating conditional probabilities using Bayes' theorem.
- How to calculate expected value
Learn how to calculate the expected value of a discrete random variable by summing the products of each possible outcome and its probability.
- How to find a probability with the normal distribution
Learn how to find normal distribution probabilities by calculating z-scores and evaluating the standard normal cumulative distribution function.
- How to calculate a binomial probability
Learn how to calculate the probability of exactly k successes in n independent Bernoulli trials using the binomial probability formula.
- How to calculate a weighted mean
Learn how to calculate a weighted mean by multiplying each value by its weight and dividing by the sum of the weights.
- How to find quartiles and the interquartile range
Learn to calculate the first, second, and third quartiles of a dataset and compute the interquartile range (IQR).
- How to calculate the standard deviation of a sample
A precise, step-by-step method to compute the sample standard deviation using the sum of squared deviations divided by n-1.