### Question:
StatisticsMath { public static <T extends Number> double std(final List<T> values) { return SumatraMath.sqrt(variance(values)); } @SuppressWarnings("unused") private  StatisticsMath(); static double mean(final List<T> values); static double median(final List<T> values); static double variance(final List<T> values); static double std(final List<T> values);  }### Answer:
@Test public void testStd() { Assertions.assertThat(StatisticsMath.std(Arrays.asList(12, 19, 42, 1337))).isCloseTo( SumatraMath.sqrt(StatisticsMath.variance(Arrays.asList(12, 19, 42, 1337))), Assertions.withinPercentage(0.01)); }