RunningStats { public double mean() { return mean1; }  void push(double x); double mean(); double variance(); double stddev(); double skewness(); double kurtosis();  }
@Test public void testMean() { RunningStats runningStats = new RunningStats(); runningStats.push(0.0d); runningStats.push(40.0d); runningStats.push(100.0d); runningStats.push(100.0d); Assert.assertEquals(60.0d, runningStats.mean(), 0.001); }
@Test public void testMeanWithNoEntry() { RunningStats runningStats = new RunningStats(); Assert.assertEquals(0.0d, runningStats.mean(), 0.001); }