Democratic (Examples 15, 16, 17, 18) Voters and the FBI In 2003 and 2017 Gallup asked Democratic voters about their views on the FBI. In 2003, 44 % thought the FBI did a good or excellent job. In 2017, 69 % of Democratic voters felt this way. Assume these percentages are based on samples of 1200 Democratic voters. a. Can we conclude, on the basis of these two percentages alone, that the proportion of Democratic voters who think the FBI is doing a good or excellent job has increase from 2003 to 2017? Why or why not? b. Check that the conditions for using a two-proportion confidence interval hold. You can assume that the sample is a random sample. c. Construct a 95 % confidence interval for the difference in the proportions of Democratic voters who believe the FBI is doing a good or excellent job, p 1 − p 2 . Let p 1 be the proportion of Democratic voters who felt this way in 2003 and p 2 be the proportion of Democratic voters who felt this way in 2017. d. Interpret the interval you constructed in part c. Has the proportion of Democratic voters who feel this way increased? Explain.
Democratic (Examples 15, 16, 17, 18) Voters and the FBI In 2003 and 2017 Gallup asked Democratic voters about their views on the FBI. In 2003, 44 % thought the FBI did a good or excellent job. In 2017, 69 % of Democratic voters felt this way. Assume these percentages are based on samples of 1200 Democratic voters. a. Can we conclude, on the basis of these two percentages alone, that the proportion of Democratic voters who think the FBI is doing a good or excellent job has increase from 2003 to 2017? Why or why not? b. Check that the conditions for using a two-proportion confidence interval hold. You can assume that the sample is a random sample. c. Construct a 95 % confidence interval for the difference in the proportions of Democratic voters who believe the FBI is doing a good or excellent job, p 1 − p 2 . Let p 1 be the proportion of Democratic voters who felt this way in 2003 and p 2 be the proportion of Democratic voters who felt this way in 2017. d. Interpret the interval you constructed in part c. Has the proportion of Democratic voters who feel this way increased? Explain.
Solution Summary: The author explains that it is impossible to conclude that the proportion of voters who think that FBI is doing good or excellent job has increased from 2003 to 2017.
Democratic (Examples 15, 16, 17, 18) Voters and the FBI In 2003 and 2017 Gallup asked Democratic voters about their views on the FBI. In 2003,
44
%
thought the FBI did a good or excellent job. In 2017,
69
%
of Democratic voters felt this way. Assume these percentages are based on samples of 1200 Democratic voters.
a. Can we conclude, on the basis of these two percentages alone, that the proportion of Democratic voters who think the FBI is doing a good or excellent job has increase from 2003 to 2017? Why or why not?
b. Check that the conditions for using a two-proportion confidence interval hold. You can assume that the sample is a random sample.
c. Construct a
95
%
confidence interval for the difference in the proportions of Democratic voters who believe the FBI is doing a good or excellent job,
p
1
−
p
2
. Let
p
1
be the proportion of Democratic voters who felt this way in 2003 and
p
2
be the proportion of Democratic voters who felt this way in 2017.
d. Interpret the interval you constructed in part
c. Has the proportion of Democratic voters who feel this way increased? Explain.
08:34
◄ Classroom
07:59
Probs. 5-32/33
D
ا.
89
5-34. Determine the horizontal and vertical components
of reaction at the pin A and the normal force at the smooth
peg B on the member.
A
0,4 m
0.4 m
Prob. 5-34
F=600 N
fr
th
ar
0.
163586
5-37. The wooden plank resting between the buildings
deflects slightly when it supports the 50-kg boy. This
deflection causes a triangular distribution of load at its ends.
having maximum intensities of w, and wg. Determine w
and wg. each measured in N/m. when the boy is standing
3 m from one end as shown. Neglect the mass of the plank.
0.45 m
3 m
Examine the Variables: Carefully review and note the names of all variables in the dataset. Examples of these variables include:
Mileage (mpg)
Number of Cylinders (cyl)
Displacement (disp)
Horsepower (hp)
Research: Google to understand these variables.
Statistical Analysis: Select mpg variable, and perform the following statistical tests. Once you are done with these tests using mpg variable, repeat the same with hp
Mean
Median
First Quartile (Q1)
Second Quartile (Q2)
Third Quartile (Q3)
Fourth Quartile (Q4)
10th Percentile
70th Percentile
Skewness
Kurtosis
Document Your Results:
In RStudio: Before running each statistical test, provide a heading in the format shown at the bottom. “# Mean of mileage – Your name’s command”
In Microsoft Word: Once you've completed all tests, take a screenshot of your results in RStudio and paste it into a Microsoft Word document. Make sure that snapshots are very clear. You will need multiple snapshots. Also transfer these results to the…
Examine the Variables: Carefully review and note the names of all variables in the dataset. Examples of these variables include:
Mileage (mpg)
Number of Cylinders (cyl)
Displacement (disp)
Horsepower (hp)
Research: Google to understand these variables.
Statistical Analysis: Select mpg variable, and perform the following statistical tests. Once you are done with these tests using mpg variable, repeat the same with hp
Mean
Median
First Quartile (Q1)
Second Quartile (Q2)
Third Quartile (Q3)
Fourth Quartile (Q4)
10th Percentile
70th Percentile
Skewness
Kurtosis
Document Your Results:
In RStudio: Before running each statistical test, provide a heading in the format shown at the bottom. “# Mean of mileage – Your name’s command”
In Microsoft Word: Once you've completed all tests, take a screenshot of your results in RStudio and paste it into a Microsoft Word document. Make sure that snapshots are very clear. You will need multiple snapshots. Also transfer these results to the…
Chapter 7 Solutions
The King's minion: Richelieu, Louis XIII, and the affair of Cinq-Mars
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