1. The population proportion of Americans with diabetes is 9 percent (π = 0.09). In repeated random samples of n = 800 Americans, 90% of sample proportions of people with diabetes would fall within ±______ from π.
a 0.01 (1.0 percentage point)
b 0.017 (1.7 percentage points)
c 0.029 (2.9 percentage points)
d 0.036 (3.6 percentage points)
2. As part of a statistics assignment in October to estimate the percentage of voters who would vote for a mayoral candidate, each of 500 students collects his or her own random sample of likely voters. There are 400 voters in each student's random sample. Each student then constructs a 95 percent confidence interval for the population proportion who will vote for the candidate using his or her own random sample. Considering the 500 intervals constructed by the students, the expected number of intervals that will contain the population proportion who will vote for that candidate will be approximately:
a 380
b 400
c 475
d 500
3. Suppose the sample proportion of one of the students in the previous question, Beth's sample, is p¯ = 0.46. Beth's 95% interval estimate of proportion of the population of voters voting for the candidate is:
a [0.41 , 0.51]
b [0.40 , 0.52]
c [0.39 , 0.53]
d [0.38 , 0.54]