1. Learning Outcome: Properly draw conclusions from confidence statements. In July 2018, the Gallup Poll asked a random sample of 1033 American adults, "Has drug abuse
been a cause of trouble in your family?" The poll found that 30% of respondents said yes, a
record high percentage since the question started being asked in 1995.
(a) What is the population for this sample survey? What is the sample? What are the numerical
values of n and p?
(b) What is the margin of error for 95% confidence for this poll? Use the "quick" method for
computing margin of error on p.43.
(c) Write a confidence statement for this poll.
(d) Explain to someone with no background in statistics why we can't just say that 30% of all
American adults would say that drug abuse has been a cause of trouble in their family.
(e) Suppose that the sample size had been 4000 rather than 1033. Find the margin of error for
95% confidence for the larger sample, and write a confidence statement for a poll with this
larger sample. (You may assume that 30% answered "yes" in this larger sample as well.)
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2. Learning Outcomes: Summarize data through numeric statistics such as the median and five-
number summary. Summarize data graphically through tools such as boxplots.
The scores of 19 students on a recent statistics quiz are shown below.
5, 7, 10, 15, 19, 21, 21, 22, 22, 23, 23, 23, 23, 23, 24, 24, 24, 24, 25
Ya) Find the five-number summary.
(b) Use the 1.5 x IQR Rule to check for outliers. Are there any outliers? If so, what are they?
(c) Construct a boxplot for this data set. If there are outliers, they should be shown on the
boxplot.
Learning Outcome. Summarize data aranhically through tools such as pie charts and bar graphs.