Mat 152 The DASH diet (Dietary Approach to Stop Hypertension) is designed to help lower blood pressure. A study is designed to determine the diet's effectiveness. A random group of 70 men with hypertension and 70 women with hypertension participate in the study. Half of the men and half of the women are randomly chosen to eat according to the DASH diet, and the remaining participants continue their regular diet. At the end of two weeks, each participant's blood pressure is measured. What is the variable of interest