import math
from typing import Iterable, List


def round_to_multiple(value: float, multiple: float) -> float:
    if multiple == 0:
        return value
    return round(value / multiple) * multiple


def cumulative_sums(values: List[float]) -> List[float]:
    if not values:
        return []
    results = [0.0] * len(values)
    results[0] = values[0]
    for i in range(1, len(values)):
        results[i] = results[i - 1] + values[i]
    return results


def standard_deviation(values: Iterable[float]) -> float:
    vals = list(values)
    n = len(vals)
    if n <= 1:
        return 0.0
    avg = sum(vals) / n
    sum_sq = sum((v - avg) ** 2 for v in vals)
    return math.sqrt(sum_sq / (n - 1))