x-correct");
    cl.remove("webex-incorrect");
  } else if (real_answers.includes(my_answer)) {
    cl.add("webex-correct");
    cl.remove("webex-incorrect");
  } else {
    cl.add("webex-incorrect");
    cl.remove("webex-correct");
  }

  // match numeric answers within a specified tolerance
  if(this.dataset.tol > 0){
    var tol = JSON.parse(this.dataset.tol);
    var matches = real_answers.map(x => Math.abs(x - my_answer) < tol)
    if (matches.reduce((a, b) => a + b, 0) > 0) {
      cl.add("webex-corre