Arthur is interested in the effects of sleep deprivation usage on number of calories consumed. He asks a group of 20 college students to spend the night in the sleep lab under one of these conditions: no sleep, 2 hours of sleep, 4 hours of sleep, 6 hours of sleep, or 8 hours of sleep. Arthur measures how many calories are consumed by the students in the sleep lab, which is stocked with various food items. After collecting these data, Arthur performs an ANOVA and finds that he can reject the null hypothesis. On the basis of this, what does Arthur know