Blood donations from volunteers serve a crucial role in the nation's health care system. Are Americans any more or less generous about donating blood in some years than others? Are women any more or less willing to give blood than men? To investigate these questions we can analyze data from the General Social Survey, which is a national survey conducted every two years on a nationwide random sample of adult Americans. 1. Did this study make use of random sampling, random assignment, both, or neither? Also explain what your answer means in terms of the scope of conclusions that can be drawn from these data. Let's start by comparing the years 2002 and 2004. 2. State the appropriate null and alternative hypotheses, in words and in symbols, to address the research question of whether Americans were more generous with blood donations in one of these years than the other. (Hint: Remember that hypotheses are always about population parameters, and think about whether the alternative should be one- or two-sided before you see the data.) Data from the 2002 and 2004 surveys are summarized in this two-way table: 2002 2004 Donated blood in previous 12 months 210 230 Did not donate blood in previous 12 months 1,152 1,106 Total 1,362 1,336