In June 2015, Gallup conducted a poll of a random sample of 14,683 adults to determine the well-being of people living in the United States. One question asked, “Did you exercise at least 30 minutes for 3 or more days in the past week?” In the survey, 58.9% of males and 52.7% of females responded yes to this question. Which of the following is true about this scenario? 58.9% and 52.7% are both parameters. 58.9% and 52.7% are both statistics. If we took another random sample of 14,683 adults, we would expect to get the exact same results.

A social scientist wishes to conduct a survey. She plans to ask a yes/no question to a random sample from the U.S. adult population. One proposal is to select 100 people; another proposal is to select 900 people.Which one of the following is true regarding the standard deviation of the sampling distribution of the sample proportion, p̂, of "yes" responses?Group of answer choicesThe standard deviation of the sampling distribution will be the same for both sample sizes.The standard deviation of the sampling distribution will be 3 times larger with sample size 100.The standard deviation of the sampling distribution will be 9 times smaller with sample size 100.The standard deviation of the sampling distribution will be 9 times larger with sample size 100.The standard deviation of the sampling distribution will be 3 times smaller with sample size 100.

In a survey, editors of a magazine asked 100 people whether or not they smoke and whether or not they exercise regularly (more than twice a week). The results are summarized in the table below.  Smoke Do not smokeExercise regularly 6 12Do not exercise regularly 18 64(a) What percentage of the adults exercise regularly?%(b) What percentage of the adults smoke?%

A social scientist wishes to conduct a survey. She plans to ask a yes/no question to a random sample from the U.S. adult population. One proposal is to select 100 people; another proposal is to select 900 people.If the study were conducted repeatedly (selecting different samples of people each time), which one of the following would be true regarding the resulting sample proportions of "yes" responses? Different sample proportions would result each time, but for sample size 900 they would be centered (have their mean) at the true population proportion, whereas for sample size 100 they would not. For either sample size, using the same size each time, as long as the sampling is done with replacement, their mean would be 0. Different sample proportions would result each time, but for either sample size, they would be centered (have their mean) at the true population proportion. Different sample proportions would result each time, but for sample size 100 they would be centered (have their mean) at the true population proportion, whereas for sample size 900 they would not.

A social scientist wishes to conduct a survey. She plans to ask a yes/no question to a random sample from the U.S. adult population. One proposal is to select 100 people; another proposal is to select 900 people.Which of the following is true regarding the sample proportion p̂ of "yes" responses? The sample proportion from the sample of 900 is more likely to be close to the true population proportion, p. The sample proportion from sample of 100 is more likely to be close to the true population proportion, p. The sample proportion in either proposal is equally likely to be close to the true population proportion, p, since the sampling is random.

Researchers were interested in determining if grumpy old men were more likely to suffer heart disease than contented old men. A random sample of 300 men, aged between 55 and 65 years of age, was surveyed and their responses were recorded. Of the 100 grumpy old men surveyed 5 suffered from heart disease; of the 200 contented old men surveyed, 20 suffered from heart disease. Based on this information, which one of the following statements is FALSE?Group of answer choicesThe estimated difference in the incidence of heart disease for the two groups is -0.05.For constructing an approximate 95% confidence interval for (pgrumpy - pcontent ),the standard error is 0.0304.To test the hypothesis:   Ho : pgrumpy - pcontent = 0    against a two-sided alternative, the standard error will necessarily be greater than the standard error used for constructing the corresponding confidence interval.If we doubled the sample size, but still observed that 5% of the old grumpy men suffered from heart disease and 10% of the contented old men suffered from heart disease, then we would conclude that, for this age group, grumpy old men are (significantly) less likely to suffer from heat disease than contented men of a similar age.From this sample we can conclude that grumpy men, aged 55 to 65 years old, are (significantly) less likely to suffer from heart disease than contented men of a similar age.