25. \(H_{0}:\) The time of day has no effect on the mean number of vacuum sales. \(H_{1}:\) The time of day has an effect on the mean number of vacuum sales. \(H_{0}:\) There is no interaction effect ...25. \(H_{0}:\) The time of day has no effect on the mean number of vacuum sales. \(H_{1}:\) The time of day has an effect on the mean number of vacuum sales. \(H_{0}:\) There is no interaction effect between time of day and type of vacuum on the mean number of vacuum sales. \(H_{1}:\) There is an interaction effect between time of day and type of vacuum on the mean number of vacuum sales.