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Years Of Experience
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Students Taught
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Projects Consulted
ANOVA & Post-Hoc Tests
Bonferroni Correction Calculator
Adjust your significance threshold when running multiple comparisons, reducing the risk of false positives.
Games-Howell Test Calculator
Run post-hoc pairwise comparisons after ANOVA when your groups have unequal variances or sample sizes.
One Way ANOVA Calculator
Test whether means differ significantly across three or more independent groups. Get F-statistic, p-value, and full...
Tukey HSD Post Hoc Calculator
Identify exactly which group pairs differ significantly after finding a significant ANOVA result.
Two-Way ANOVA with Replication Calculator
Test the effects of two independent factors and their interaction, with multiple observations per group.
Two-Way ANOVA Without Replication Calculator
Test the effects of two independent factors when you have only one observation per combination.
Confidence Intervals
Confidence Interval One Sample T Test: Formula, Calculation, and Free Calculator
Build a confidence interval for a population mean from one sample when the population standard deviation...
Confidence Interval One Sample Z Test
Estimate a confidence interval for a population mean when the population standard deviation is known.
Confidence Interval Paired T Test Calculator
Find the confidence interval for the mean difference between paired measurements, such as before-and-after data from...
Confidence Interval Two Proportion Z Test Calculator
Estimate the confidence interval for the difference between two population proportions. Compare two groups' success rates.
Confidence Interval Two Sample T Test (Equal Variance)
Compare two independent sample means with equal variances and get the confidence interval for the difference.
Confidence Interval Two Sample T Test (Unequal Variance)
Compare two independent sample means with unequal variances and get the confidence interval for the difference.
Confidence Interval Two Sample Z Test Calculator
Build a confidence interval for the difference between two population means when both population standard deviations...
One Proportion Z Interval Calculator: Formula, Conditions, Examples & Software Steps
Build a confidence interval for a single population proportion, with full formula and step-by-step explanation.
Descriptive Statistics
Boxplot plot and Five Number Summary Calculator
Generate a boxplot and full 5-number summary instantly. See step-by-step calculations for IQR, quartiles, and outlier...
Coefficient of Variation Calculator
Measure relative variability (CV) by comparing standard deviation to the mean. Useful for comparing spread across...
Empirical Rule Calculator: How I Use the 68-95-99.7 Rule to Read Any Bell Curve in Seconds
Apply the 68-95-99.7 rule to quickly estimate what percentage of your data falls within 1, 2,...
Interquartile Range (IQR) Calculator
Find Q1, Q3, the interquartile range, and outlier boundaries instantly from your dataset.
Measures of Central Tendency Calculator
Find the mean, median, and mode of your dataset instantly, with a clear breakdown of each...
Standard Deviation Calculator
Calculate the standard deviation of your dataset to measure how spread out your values are from...
Diagnostics & Model Checking
Breusch-Pagan Test Calculator
Run the Breusch-Pagan test for heteroscedasticity in your regression model. Get the LM statistic, p-value, and...
Critical F Score Calculator
Find the critical F value for your significance level and degrees of freedom. Used to determine...
Durbin-Watson Calculator
Detect autocorrelation in your regression residuals to check whether this key assumption is met.
Shapiro Wilk Test Calculator
Test whether your sample data is consistent with a normal distribution before choosing a statistical test.
Which Statistical Test to Use? Interactive Guide
Answer a few questions about your data and research question to find the right statistical test...
Distributions
Binomial Distribution Calculator
Calculate binomial probability, mean, and variance instantly. Enter your number of trials and success probability to...
Hypergeometric Distribution Calculator
Calculate the probability of drawing a specific number of successes from a finite population without replacement.
Normal Distribution Calculator
Find the probability that a value falls above, below, or between two points on a normal...
P-Value Calculator
Calculate the p-value for your test statistic across z, t, chi-square, and F distributions.
Poisson Distribution Calculator
Calculate the probability of a specific number of events occurring in a fixed time or space...
Probability Distribution Calculator
Enter any set of outcomes and probabilities to instantly get the mean, variance, and expected value.
Non-Parametric Tests
Chi Square Goodness of Fit Calculator
Test whether your observed data matches an expected distribution across categories.
Chi Square Test of Independence Calculator
Test whether two categorical variables are related using a contingency table of observed frequencies.
Critical Chi-Square Calculator
Find the critical chi-square value for your significance level and degrees of freedom, used in chi-square...
Dunn’s Test Calculator
Run pairwise comparisons between groups after a significant Kruskal-Wallis test.
Friedman Test Calculator
Compare three or more matched groups or repeated measures without assuming a normal distribution.
Kruskal Wallis Test Calculator
Compare three or more independent groups without assuming a normal distribution, using the Kruskal-Wallis test.
Mann Whitney U Test Calculator
Compare two independent groups when your data doesn't meet the assumptions for a t-test.
Wilcoxon Signed Rank Test Calculator
Compare two related (paired) samples when your data doesn't meet the assumptions for a paired t-test.
Power & Sample Size
Sample Size Calculator
Determine the sample size you need for your study based on confidence level, margin of error,...
Sample Size Power Calculator
Determine the sample size you need to detect a meaningful effect at your desired power level.
Statistical Power Calculator
Estimate the probability that your test will correctly detect a real effect, given your sample size...
Regression & Correlation
Cook’s Distance Calculator
Identify influential data points in your regression model using Cook's Distance, with a diagnostic plot.
Correlation Coefficient Calculator
Measure the strength and direction of a linear relationship between two variables using Pearson's correlation coefficient.
Covariance Calculator: Calculate, Interpret, and Use It Correctly (With Steps)
Measure how two variables change together. Enter paired data to see whether they move in the...
Logistic Regression Calculator
Model the probability of a binary outcome based on one or more predictor variables using logistic...
Multiple Linear Regression Calculator
Model the relationship between one outcome variable and multiple predictors, with full coefficient output.
Odds Ratio Calculator
Calculate the odds ratio to compare the odds of an outcome between two groups.
Regression Assumption Checker by Statssy
Check whether your regression model meets key assumptions before trusting the results.
Risk Ratio Calculator
Calculate the risk ratio to compare the probability of an outcome between two groups.
ROC/AUC Calculator
Evaluate a classification model's performance using ROC curve and AUC score.
Simple Linear Regression Calculator
Find the slope, intercept, and R-squared for the linear relationship between two variables.
Spearman Rank Correlation Calculator
Measure the strength of a monotonic relationship between two variables, ideal for ordinal or non-linear data.
VIF Calculator
Detect multicollinearity between your predictor variables before trusting your regression coefficients.
Reliability & Effect Size
Cohen’s d Calculator
Measure the standardized difference between two group means. Includes automatic interpretation of effect size and a...
Cohen’s Kappa Calculator
Measure how well two raters agree on categorical classifications, correcting for agreement expected by chance.
Cronbach’s Alpha Calculator
Measure the internal consistency reliability of your survey or test items using Cronbach's alpha.
Effect Size Calculator
Measure the practical significance of a difference between groups, not just statistical significance.
Z & T Tests
Critical T Score Calculator: Find Your Exact Critical Value (Any df, Any Alpha)
Find the critical t value for your significance level and degrees of freedom, used to determine...
Critical Z Score Calculator
Find the critical z value for your chosen significance level and test type (one- or two-tailed).
Fisher’s Exact Test Calculator
Test independence between two categorical variables in a 2x2 table, especially useful for small samples.
Margin of Error Calculator
Calculate the margin of error for your survey or study based on sample size, confidence level,...
One Proportion Z Test Calculator
Test whether your sample proportion differs significantly from a hypothesized population value.
One Sample T Test Calculator
Test whether your sample mean differs significantly from a known or hypothesized value.
One Sample Z Test Calculator
Test whether your sample mean differs from a known population mean when the population standard deviation...
Two Proportion Z Test Calculator
Test whether two population proportions differ significantly. Compare success rates between two independent groups.
Two Sample T Test (Equal Variance)
Compare two independent sample means assuming equal variances, with full t-statistic and p-value output.
Two Sample Z Test Calculator
Test whether two population means differ significantly when both population standard deviations are known.
z Score Calculator
Find how many standard deviations a value is from the mean, and its corresponding percentile.
Process
How our tutoring and consultation works in 3 simple steps
Connect
Tell us what you want to learn. Schedule a quick call or drop a message with your learning goals.Tell us what you want to learn. Schedule a quick call or drop a message with your learning goals.
Collaborate
We create a personalized learning plan based on your goals and conduct interactive online tutoring sessions focused on building your understanding.
Deliver
Build confidence in statistics through practical examples, guided problem-solving, and one-to-one instruction.