{
  "array": [0, 10, 20, 30],
  "expected": {
    "mean": 15,
    "median": 15,
    "p90": 27,
    "p95": 28.5,
    "p99": 29.7,
    "p999": 29.97,
    "stddev": "sqrt(500/3)",
    "variance_sum_of_squares": 500,
    "percentile_method": "LINEAR_N_MINUS_ONE"
  }
}