Functional solution for computing geometric mean in Java

gistfile1.java

package com.jnape.dynamiccollection;

import com.jnape.dynamiccollection.lambda.Accumulator;

import static com.jnape.dynamiccollection.factory.DynamicListFactory.list;
import static java.lang.Math.pow;

public class GeometricMean {

    public static final Accumulator<Integer, Integer> TIMES = new Accumulator<Integer, Integer>() {
        @Override
        public Integer apply(Integer product, Integer number) {
            return product * number;
        }
    };

    public static Number geometricMean(Integer... numbers) {
        return pow(list(numbers).reduce(TIMES), 1f / numbers.length);
    }
}