A poll in November 2013 found that 52% of the people in the sample said they wan
ID: 3221433 • Letter: A
Question
A poll in November 2013 found that 52% of the people in the sample said they want to lose weight. They announced, "For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±3 percentage points."
(a) What is the 95% confidence interval for the percent of all adults who want to lose weight? (Enter your answers as whole numbers.)
______ to _________ %
(b) What does it mean to have 95% confidence in this interval?
a. 95% confidence means that this interval was produced using a process for which there is a 95% chance the interval contains the actual percent of adults in the population who want to lose weight.
b. 95% confidence means that this interval was produced using a process for which, in the long run, 95% of all samples of the same size give an interval that contains the actual percent of adults in the population who don't want to lose weight.
c. 95% confidence means that this interval was produced using a process for which there is a 95% chance the interval contains the actual percent of adults in the population who don't want to lose weight.
d. 95% confidence means that this interval was produced using a process for which there is a 95% chance the midpoint of the interval is the actual percent of adults in the population who want to lose weight.
e. 95% confidence means that this interval was produced using a process for which, in the long run, 95% of all samples of the same size give an interval that contains the actual percent of adults in the population who want to lose weight.
Explanation / Answer
p = 0.52 , ME = 3
a) CI = p + / - ME
= 52 + /- 3
= (49 , 55)%
b)
e. 95% confidence means that this interval was produced using a process for which, in the long run, 95% of all samples of the same size give an interval that contains the actual percent of adults in the population who want to lose weight.