Note: Parts a. and b. of this question relate to this newspaper clipping from The Globe and Mail, April 15, 1994: Stressful jobs raise men's blood pressure Difficult work could damage circulatory system, study finds Associated Press (AP) BOSTON - Men with stressful jobs have higher-than-usual blood pressure even when they sleep, suggesting that such difficult work permanently damages their circulatory systems, a new study indicates. Working women are less likely than men to show the effects of job stress, but their blood pressure is more likely to soar in response to stress at home, especially problems with children, another study finds. The studies were among several presented yesterday that strengthen the belief that highly demanding jobs in which people have little control are especially bad for health. But they caution that what happens off the job matters too. "It would be particularly naive to think that any job strain explains everything. It's only part of the day", said Dr. Thomas Pickering of New York Hospital. To delve into these questions, researchers hooked up volunteers to portable monitors and watched how their blood pressure went up or down in response to the day's challenges. They presented their findings at a meeting of the Society of Behavioral Medicine. Dr. Joseph Schwartz and others from the State University of New York at Stony Brook followed 373 men and women who worked in nine different places in New York City. They found that people in highly demanding jobs with little autonomy had significantly higher blood pressures than did those in less taxing situations, including people with stressful jobs who could make their own decisions and those in easy-going positions who had little opportunity to think for themselves. Those in high-stress, low freedom jobs had blood pressures that averaged between 137 over 85, versus about 129 over 83 for the other people. The difference grows progressively greater as people get older. Normal blood pressure is 120 over 80. Ordinarily, blood pressure fluctuates over the course of the day, depending on a person's activity, and this may be harmless. However, for those in high-strain positions, blood pressure tended to stay high. Their reading were above those of other people's while at home in the evening, and even as they slept."No one can say which came first, the job stress, or the high blood pressure", Dr. Schwartz said. For instance, it is possible that people with type A personalities already have high blood pressure and are attracted to punishing jobs. However, he said his data suggest that the "cumulative effect of the exposure to stress over time" permanently raises blood pressure. a. Answer these questions about the Problem Stage. Describe the target population. ii. What is the response variable? iii. What is the main explanatory variable? b. Answer the following question: about the Plan Stage. Describe the study population