### Question:
Statistics { public BigDecimal standardDeviation() { BigDecimal z = new BigDecimal(values).multiply(new BigDecimal(values)).divide( new BigDecimal(counter), PRECISION_INTERNAL); BigDecimal variance = new BigDecimal(square).subtract(z).divide( new BigDecimal(counter - 1), PRECISION_INTERNAL); return sqrt(variance).round(PRECISION); } Statistics(String meteringPointName); void addValue(long actual); BigDecimal average(); BigDecimal standardDeviation(); List<Average> getAverages(); long getCounter(); long getLast(); long getMaximum(); String getMeteringPointName(); long getMinimum(); long getValues(); static final String[] TITLES; }### Answer:
@Test public void testStandardDeviation() { assertThat(classUnderTests.standardDeviation(), is(STDDEV)); }