e (or
<em>mean</em>) value of a variable. A one-sample t-test asks whether the
mean of the distribution from which a sample is drawn is equal to some
fixed value. A two-sample t-test asks whether the difference in means
between two distributions is equal to some value (often zero, i.e., no
difference in means).</p>
<p>Our function <code><a href="../reference/ttest.html">ttest()</a></code> is flexible, allowing
stratification, calculation of the geometric mean, and equal/unequal
variances between samples. Fo