Practice Final
1
Problem 1 Identifying elements of a study and appropriate statistical inference
From January 5 to 7, 2015, Hart Research Associates conducted a national survey on the issue of the federal
minimum wage. Interviews were conducted online among a representative national sample of 1,002 adults.
Respondents answered the following question:
“Do you support raising the federal minimum wage to
$15.
00/hour over the next 5 years?”
The only options were "Support" and "Do not support".
The survey
results showed that 63% of those who responded supported this proposal.
1.1
What kind of study is this?
a)
Cross-sectional survey
b)
Prospective longitudinal cohort
c)
Case-control study
d)
Cross-sectional experiment
e)
None of the above

1.2
What is the population parameter of
interest?

1.3
What is the distribution of the individual-
level outcome in the population?

1.4
What is the distribution of the combination
of outcomes in the population?

For the next section, use
?
for the population parameter,
?̂
for the sample estimate and
?
0
for the
𝐻
0
value.
1.5
What is the approximate sampling
distribution of the sample estimate?
(show formula with expected value and standard deviation)
?̂ ~ ? (?,
√
?(1 − ?)
?
)
1.6
What is the sampling distribution of the
estimate under the null hypothesis
𝐻
0
: ? = ?
0
? (?
0
,
√
?
0
(1 − ?
0
)
?
)
1.7
Plug in the values to 1.6 that you would use
to test the hypothesis that public opinion is
evenly split on raising the federal minimum
wage to $15/hr.
? (0.5,
√
0.5(1 − 0.5)
1002
)
1.8
What is the estimate of the sampling
distribution of
?̂
for constructing a
confidence interval?
?
? (?̂,
√
?̂(1 − ?̂)
?
)

Practice Final
2
1.9
Plug in the values to 1.8 that you would use
for the confidence interval for the poll
estimate of the fraction who support raising

the federal minimum wage to $15/hr.
The poll was reported to have a margin of error of ± 3%.
What is the formula they used to calculate this value,
and what values would you plug in to obtain a 95% confidence interval?
m

1.11
Plug in the values to calculate the margin
of error for a 95% Confidence Interval.

Practice Final
3