exam 3

The article "Teenage Physical Activity Reduces Risk of Cognitive Impairment in Later Life"+ describes a study of more than 9,000 women from Maryland, Minnesota, Oregon, and Pennsylvania. The women were asked about their physical activity as teenagers and at ages 30 and 50. A press release about this studyt generalized the results of this study to all American women. In the press release, the researcher who conducted the study is quoted as saying the following. Our study shows that women who are regularly physically active at any age have lower risk of cognitive impairment than those who are inactive but that being physically active at teenage is most important in preventing cognitive impairment. Answer the following four questions for this observational study. (a) What is the population of interest? O all teenage girls all women in Maryland, Minnesota, Oregon and Pennsylvania all women all women between 30 and 50 all American women (b) Was the sample selected in a reasonable way? O No,…

Studies have suggested that alcohol abuse and disorders are found to be more prevalent during early adulthood than in any other age group, with about 9% of young adults (age 18 to 29 years) meeting the criteria to be labeled as alcoholic. In addition, surveys have shown that college students tend to drink more than their peers who do not attend college. You want to test to see if there are differences in excessive alcohol use in young adults that attend college versus those who do not, so you surveyed 405 young adults, age 19 to 22, about their alcohol use by asking the question, "Have you consumed alcohol to the point of intoxication at least once within the past month?" with the following results. Young Adults Attending College Young Adults Not Attending College n1 = 255 n2 = 150 y1 = 96  said "yes" y2 = 44  said "yes" p̂1 =  96 255 p̂2 =  44 150   (a) Calculate the test statistic. (Round your answer to two decimal places.)   (b) If  H0:…

If the alternative hypothesis states that alcohol affects short-term memory, the null hypothesis states O alcohol does not affect short-term memory O alcohol decreases short-term memory alcohol does not decrease short-term memory