void page4() {
  String t = "Step 4 - The p-value";
  textFont(myboldfont, 18);
  text(t, 30, 170);
  textFont(myfont, 18);

  t = "Use Table A.3 in the back of the book to the find the area to the left of z* under N(0,1): ";
  drawStrings(t, 30, 200, 25);

  float rowl, coll, rowu, colu;

  if (testl > 3.69) {
    rowl = 3.6;
    coll = 0.09;
  }
  else if (testl < -3.69) {
    rowl = -3.6;
    coll = 0.09;
  }
  else { 
    //rowl = int(testl * 10.0) / 10.0;
    //coll = round(abs(testl-rowl) * 100.0) / 100.0;
    rowl = float(round(testl*100.0)/10)/10.0;
    coll = abs(float(round(testl*100.0)%10)/100.0);
  }

  if (testu > 3.69) {
    rowu = 3.6;
    colu = 0.09;
  }
  else if (testu < -3.69) {
    rowu = -3.6;
    colu = 0.09;
  }
  else { 
    //rowu = int(testu * 10.0) / 10.0;
    //colu = round(abs(testu-rowu) * 100.0) / 100.0;
    rowu = float(round(testu*100.0)/10)/10.0;
    colu = abs(float(round(testu*100.0)%10)/100.0);
  }

  if (rowu<0) {
    pu = (float)(Probability.normcdf(rowu-colu));
  }
  else {
    pu = (float)(Probability.normcdf(rowu+colu));
  }

  if (rowl<0) {
    pl = (float)(Probability.normcdf(rowl-coll));
  }
  else {
    pl = (float)(Probability.normcdf(rowl+coll));
  }

  pl = float(round(pl*10000))/10000;
  pu = float(round(pu*10000))/10000;

  if (aStudy.k==0) {
    text(nf(coll, 1, 2), 240, 250);
    text(nf(rowl, 1, 2), 130, 320);
    text(nf(pl, 1, 4), 230, 320);

    image(smalldown, 240, 260);
    image(smallright, 185, 295);

  }
  else if (aStudy.k==1) {
    text(nf(colu, 1, 2), 240, 250);
    text(nf(rowu, 1, 2), 130, 320);
    text(nf(pu, 1, 4), 230, 320);

    image(smalldown, 240, 260);
    image(smallright, 185, 295);

  }
  else {
    text(nf(coll, 1, 2), 240, 250);
    text(nf(rowl, 1, 2), 130, 320);
    text(nf(pl, 1, 4), 230, 320);

    image(smalldown, 240, 260);
    image(smallright, 185, 295);

    text("To the left of Z_l", 140, 360);

    text(nf(colu, 1, 2), 495, 250);
    text(nf(rowu, 1, 2), 380, 320);
    text(nf(pu, 1, 4), 480, 320);

    image(smalldown, 495, 260);
    image(smallright, 435, 295);

    text("To the left of Z_u", 390, 360);
  }
}