StatisticsdrillPaired t test
A statistics problem from Statisticsdrill. Solve it with one answer box, with a fresh sample on every attempt and the worked steps and spreadsheet function in the answer, and it is checked the moment you submit.
The task
6 employees took a skills test before and after a training course (same people, so the scores are paired). Before: 90, 78, 71, 66, 69, 59. After: 87, 77, 65, 58, 69, 56. Find the paired t statistic for the mean change (after minus before), then test H0: μd = 0 against H1: μd ≠ 0 at α = 0.05. Round to 2 decimal places.
What this problem teaches
The formula: d = after - before: -3, -1, -6, -8, 0, -3.
A hint if you get stuck
Work with the differences d = after - before: t = d̄ / (s_d / √n), with n - 1 degrees of freedom.
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