In view of the small variation in the products sold by machines in a previous study,14 we included the lowest number of these that would make for a distribution similar to that of the original sample food, drink and mixed.
Dada la escasa variación en los productos de las máquinas en un estudio previo, se incluyó el menor número de ellas que permitiera mantener una distribución similar a la muestra original comida, bebida y mixto.