A polling agency conducted a survey of 100 doctors on the question: Are you willing to treat women patients with the recently approved pill RU-486? The conservative margin of error associated with the 95 confidence interval for the percent who say yes' is
a. 50.
b. 10.
c. 5.
d. 2.
Q. 2A recent poll reported that 62 of all college students believe there is extraterrestrial life. The 95 margin of error for the poll was 4. Which of the following statements is correct?
a. We can be certain that the percentage of all college students who believe there is extraterrestrial life is in the interval 58 to 66.
b. The chance is 95 that at least 62 of all college students believe there is extraterrestrial life.
c. With 95 confidence we can say that the percentage of all college students who believe there is extraterrestrial life is between 58 and 66.
d. The chance is 5 that at least 62 of all college students believe there is extraterrestrial life.
Q. 3According to a Gallup poll, about 90 of all American adults owned a cell phone at the time of the poll. The results are based on telephone interviews with a randomly selected national sample of 998 adults, 18 years and older. The margin of error was reported to be 3.5. Which of the following statements correctly interprets the reported margin of error of 3.5?
a. In about 95 of all random samples of this size from the same population, the difference between the sample percent and the population percent will be less than 3.5.
b. In about 3.5 of all random samples of this size from the same population, the sample percent will equal the population percent.
c. The probability that a 95 confidence interval based on this poll does not cover the population proportion is 3.5.
d. In about 95 of all random samples of this size from the same population, the difference between the sample percent and the population percent will be more than 3.5.
Q. 4According to a Gallup poll, about 90 of all American adults owned a cell phone at the time of the poll. The results are based on telephone interviews with a randomly selected national sample of 998 adults, 18 years and older. The margin of error was reported to be 3.5. What was the population of interest in this Gallup Poll?
a. All American adults who own cell phones.
b. All American adults.
c. The 998 adults who participated in the survey.
d. The participants in the survey who owned cell phones.
Q. 5A Gallup poll reported that 58 of Americans say they are satisfied with the costs of healthcare. If the margin of error was 5, approximately what was the sample size?
a. 10
b. 200
c. 400
d. 1600
Q. 6A Gallup poll reported that 88 of Americans say they have health insurance. If the sample size was 2500, an approximate 95 confidence interval for the proportion of all Americans who say they are insured is
a. between 80 and 96.
b. between 84 and 92.
c. between 86 and 90.
d. between 87.3 and 88.7.