A survey of 1,200 college students in midNovember 2004 asked, "Outside of class, how often do you discuss politics and current events?" Based on their responses, a 95% confidence interval for the proportion of all students who would answer "almost every day" is (0.30, 0.36).
a. What is the point estimate for population proportion?
b. What is the margin of error in this estimate?
c. What is the approximate standard deviation of the sample proportion?
d. Would a 99% confidence interval be wider or narrower?
e. Tell which one of these is the correct interpretation of the interval (0.30, 0.36):
1. The probability is 0.95 that the sample proportion falls in this interval.
2. The probability is 0.95 that the population proportion falls in this interval.
3. We are 95% confident that the sample proportion falls in this interval.
4. We are 95% confident that the population proportion falls in this interval.
f. Is the interval approximately accurate for any year, or just for 2004 (a presidential election year)? Explain.
g. Is the interval approximately accurate for any month that year, or just for November? Explain.