Turning in DiceRolling-Lab.

Answers.md

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+1. Probability of rolling a seven is 1 / 6.  Probability of rolling a 2 is 1 / 36.
+
+2. The bulk of the values is around the middle numbers such as 5 through 9.  100 rolls is not efficient to determine the frequency.
+
+3. The highest frequency of values are still 5 through 9 but they seem to overall be closer.
+
+4. At 500,000 rolls you can accurately predict the probability of rolling a 7 to 3 significant digits.  At 300,00 rolls you can accurately predict the probability of rolling a 2 to 3 significant digits.

src/Histogram.java

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+public class Histogram {
+  private int[] data = new int[13];
+  private int count = 0;
+
+  public void tally(int roll) {
+    data[roll] += 1;
+    count += 1;
+  }
+
+  public int getCount(int roll) {
+    return data[roll];
+  }
+
+  public double getRatio(int roll) {
+    return data[roll] / (double) count;
+  }
+
+  public void print() {
+    int val = 2;
+    while (val <= 12) {
+      System.out.println(val +"/" + data[val] + "*" + getRatio(val));
+
+      val += 1;
+    }
+  }
+}

src/Main.java

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+public class Main {
+  public static void main(String[] args) {
+
+    int total = 0;
+
+    Histogram h = new Histogram();
+
+    Die d1 = new Die();
+    Die d2 = new Die();
+
+    for(int i = 0; i < 300000; i++) {
+      d1.roll();
+      d2.roll();
+      total = d1.getUpValue() + d2.getUpValue();
+      h.tally(total);
+    }
+    h.print();
+  }
+}
+
+
+