tion" id="toc-exponential-distribution" class="nav-link" data-scroll-target="#exponential-distribution">Exponential distribution</a>
  <ul class="collapse">
  <li><a href="#probability-density-function-4" id="toc-probability-density-function-4" class="nav-link" data-scroll-target="#probability-density-function-4">Probability density function</a></li>
  <li><a href="#sampling-statement-4" id="toc-sampling-statement-4" class="nav-link" data-scroll-target="#sampling-statement-4">Sampling statement</a></li>
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