25. H0: The time of day has no effect on the mean number of vacuum sales. H1: The time of day has an effect on the mean number of vacuum sales. H0: There is no interaction effect ...25. H0: The time of day has no effect on the mean number of vacuum sales. H1: The time of day has an effect on the mean number of vacuum sales. H0: There is no interaction effect between time of day and type of vacuum on the mean number of vacuum sales. H1: There is an interaction effect between time of day and type of vacuum on the mean number of vacuum sales.