Statistics
By Dr. Akash Garg, DC, MS Pharmacology, MEd, MBA · Updated October 20, 2026
Turn data into decisions you can defend. Free to read, practice and play, with no sign-up.
14chapters
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Chapters
- 1What Statistics IsDescriptive vs inferential, population vs sample, types of data & levels of measurement
- 2Sampling & Data CollectionRandom sampling methods, bias, observational studies vs experiments & design
- 3Displaying DataFrequency tables, bar charts, histograms, distribution shape & misleading graphs
- 4Center & SpreadMean, median & mode, standard deviation, the five-number summary, boxplots & z-scores
- 5Probability BasicsSample spaces, the addition & multiplication rules, conditional probability & two-way tables
- 6Discrete Random VariablesProbability distributions, expected value, the binomial, Poisson & geometric distributions
- 7The Normal DistributionThe bell curve, the empirical rule, the standard normal & finding probabilities
- 8Sampling Distributions & the CLTThe distribution of the sample mean, the Central Limit Theorem & standard error
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- 9Confidence IntervalsInterval estimates for means & proportions, margin of error & what 95% really means
- 10The Logic of Hypothesis TestingH₀ and Hₑ, p-values, significance, Type I & II errors & practical significance
- 11One-Sample TestsThe five steps, z-tests & t-tests for a mean, tests for a proportion & assumptions
- 12Two-Sample TestsTwo independent means, paired samples, two proportions & choosing the right test
- 13Chi-Square & ANOVAGoodness of fit, tests of independence, one-way ANOVA & the F test
- 14Correlation & RegressionScatterplots, r, the least-squares line, r², residuals & the danger of extrapolation
Written by Dr. Akash Garg
Doctor of Chiropractic, MS in Pharmacology, MEd and MBA. Teaching college science since 2007.