Java Utililty Methods List Average

double avg = 0.0;
for (int i = 0, j = oper.size(); i < j; i++) {
    avg += oper.get(i).doubleValue();
return avg / oper.size();

long sumNs = 0;
for (final Long value : durations) {
    sumNs += value;
return sumNs / durations.size();

double sum = 0;
long N = 0;
if (!list.isEmpty()) {
    for (Double z : list) {
        if (z != null && !Double.isNaN(z)) {
            sum += z;
            N++;
    return (double) sum / N;
return Double.NaN;

Double sum = 0.0;
if (aList.size() > 0) {
    for (Iterator<Double> iterator = aList.iterator(); iterator.hasNext();) {
        Double double1 = iterator.next();
        sum += double1;
    return sum / aList.size();
} else {
...

if (period > timeline.size())
    return -1;
double average = 0.0;
for (int i = 0; i < period && i < timeline.size(); i++) {
    double value = timeline.get(i);
    average += value;
average /= period;
...

Double total = 0.0;
for (Number item : list) {
    total += item.doubleValue();
return total / list.size();

Double sumc = 0.0;
for (Double num : l)
    sumc += num;
return sumc / l.size();

double sum = 0d;
for (Double d : values) {
    sum += d;
return sum / values.size();

Double sum = getSum(values);
return sum / values.size();

double sum = 0;
for (double d : values)
    sum += d;
return sum / values.size();