1. A study was conducted to explore the relation between alcohol consumption and hypertension. 7400 nurses were surveyed and information about the amount of alcohol consumed per day (on average) and whether or not they suffered from hypertension was collected. The following table summarizes the information that was obtained.
Assuming the nurses surveyed were a simple random sample from the population of all nurses in the United States, the appropriate null hypothesis for these data is
A. the distribution of the average number of alcoholic drinks per day is the same for the population of nurses with hypertension and for the population of nurses who do not have hypertension.
B. the distribution of the presence of hypertension in nurses is the same for the populations of nurses who do not drink, nurses who drink 0.01 - 1.00 alcoholic drinks on average per day, nurses who drink 1.01 - 2.00 alcoholic drinks on average per day, and nurses who drink more than 2 alcoholic drinks on average per day.
C. the presence or absence of hypertension in nurses is independent of whether they do not drink, drink 0.01 - 1.00 alcoholic drinks on average per day, drink 1.01 - 2.00 alcoholic drinks on average per day, or drink more than 2 alcoholic drinks on average per day.
2. A study was performed to examine the personal goals of children in grades 4, 5, and 6. A random sample of students was selected for each of the grades from schools in Georgia. The students received a questionnaire regarding personal goals. They were asked what they would most like to do at school: make good grades, be popular, or good in sports. Results are presented in the table below by the sex of the child.
Make good grades Be popular Be good in sports
Boys 96 32 94
Girls 295 45 40
Suppose we wish to test the null hypothesis that there are no differences among the proportion of boys and the proportion of girls choosing each of the three personal goals. Under the null hypothesis, the expected number of boys that would select "be good in sports" is
A. 49.4.
B. 67.
C. 74.