= Solution
Use a \b[<Student t-test>] to assess a mean or mean difference relative to its <standard error>. A one-sample version compares a <population mean> with a specified reference. An independent two-sample version compares two separate groups, such as groups assigned different instructions; <Welch's t-test> permits unequal group <variances>. A <paired t-test> uses within-pair differences, such as each participant's before/after scores, rather than pretending those measurements are independent.<Two-Sample t-Test for Equal Means by National Institute of Standards and Technology>[Handbook Section 1.3.5.3, paired/unpaired data and equal/unequal variance cases]{ref}
The relevant <normality assumption> concerns within-group errors for the independent-groups model or the distribution of within-pair differences for the paired model. Independent participants or pairs remain essential. Report the estimated difference and its <confidence interval> together with the test result. A small <p-value> indicates incompatibility with the specified <null hypothesis> under the model; it does not measure the size of the difference, the probability that the <null hypothesis> is true, or whether the difference matters practically.
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