State the null and alternative hypotheses.

introduces a study investigating whether a brief diet intervention might improve depression symptoms. In the study, 75 college-age students with elevated depression symptoms and relatively poor diet habits were randomly assigned to either a healthy diet group or a control group. Depression levels were measured at the beginning of the experiment and then again three weeks later. The response variable is the reduction in depression level (as measured by the DASS survey) at the end of the three weeks. Larger numbers mean more improvement in depression symptoms. Test whether these experimental results allow us to conclude that, on average, improvement of depression symptoms is higher for those who eat a healthy diet for three weeks than for those who don't. The data is available on StatKey and in DietDepression. Let Group 1 represent those with a healthy diet and Group 2 represent those with no diet change. State the null and alternative hypotheses.