r the normal curve from -&#8734; up to z, the cumulative distribution
            function (cdf).
          </p>
<pre class="programlisting"><span class="comment">// For a standard normal distribution</span>
<span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"Standard normal mean = "</span><span class="special">&lt;&lt;</span> <span class="identifier">s</span><span class="special">.</span><span class="identifier">mean</span><span class="special">()</span>
  <span