Each dot plot is a sample with exactly the mean and standard deviation on the sliders. Bottom left: the sampling distributions of x̄₁ and x̄₂ (spread = s/√n) and their overlap. Bottom right: the t distribution if H₀: μ₁ = μ₂ were true, with the observed t and the two-sided p-value. t areas use an accurate Student t CDF.
Decide the design first, then compute. The worked solution builds line by line after a correct answer or when you ask for it.
Your jobEach card describes a study. Sort it into the right analysis as fast as you can: independent means (two separate groups, a measurement), paired (natural partners, analyse the differences) or two proportions (two groups, a yes/no outcome). Keys 1 2 3 pick a bin.
Press Start to begin.
Fictional settings and practice numbers chosen to look realistic. They are not clinical results, reference values or advice.
Wrong picks are fine here. Each one tells you why.