A research study was conducted to evaluate the effect of depression on sleep score in nursing home residents. Ninety residents of a nursing home facility were divided into three groups based on their level of depression: mild, moderate, or severe. The residents were then monitored overnight to obtain their sleep score. Test the hypothesis at the alpha level of .05 that the population mean sleep scores for the three groups are all equal. Assume that the sleep scores for each group follow a normal distribution and that the population variances for the three groups are all equal.
What is the dependent variable in this study?
