t-test (unpaired)

MinutePlot^® and R on the same data. MinutePlot version 1.0.0; R 4.5.2.

Dataset

• ToothGrowth (dose 2.0) — Odontoblast length in guinea pigs by supplement (R: datasets::ToothGrowth; Crampton 1947), restricted to dose 2.0 mg/day: 10 animals on orange juice (OJ), 10 on ascorbic acid (VC).
• Data format for MinutePlot: toothgrowth_dose2_minuteplot.csv — arranged exactly as the app’s data template for this test expects (paste it into the app).
• Data format for R: toothgrowth_dose2_r.csv — the long-format file the R script reads (keep it in the script’s folder).
• R built-in: the script subsets ToothGrowth (dose == 2.0) from data().

Setup

In MinutePlot:

• Workbench → t-test (unpaired) → paste toothgrowth_dose2_minuteplot.csv (OJ and VC as the two rows, ten replicates across).
• α = 0.05 → Confirm and Analyze (Welch’s test; MinutePlot offers no Student variant).

In R:

• Base R only; then run ttest_independent_toothgrowth.R top to bottom (source it, or paste it into the console) with the R data file in the same folder.
• R 4.5.2 and the package versions in the page header; each script prints the versions it runs under.

The analysis:

• Independent t-test, OJ vs VC (10 and 10), two-sided, α = 0.05. MinutePlot runs Welch’s test (unequal variances), which is also R’s default.
• Why Welch: MinutePlot performs Welch’s t-test, which does not assume equal variances and is the modern recommended default -- and R’s own default in t.test(); the Student equal-variance variant is intentionally not offered. The Student row is shown for R only, as context for readers comparing against tools that default to it (SPSS, Excel), which is why small differences can arise there.
• MinutePlot’s 95 % CI column is Hedges’ g with its CI; R’s is the CI of the mean difference.

Side-by-side results

t, df, p and 95 % confidence interval

Verdict

R script

ttest_independent_toothgrowth.R — each script loads its data, prints its versions and the R-side tables shown above, in page order; no plotting.