dard deviation of 100
            h. Assuming, perhaps with little evidence and much faith, that the distribution
            is normal, we construct a normal distribution called <span class="emphasis"><em>bulbs</em></span>
            with these values:
          </p>
<pre class="programlisting"><span class="keyword">double</span> <span class="identifier">mean_life</span> <span class="special">=</span> <span class="number">1100.</span><span class="special">;</span>
<span class="keyword">double</span> <span