When the results of a survey or poll are published, the sample size and the margin of error should both be given. For example: 1000 voters were surveyed and 39±2% of the voters agree with the president. In this example N=1000 and the margin of error (MoE) is 2%.
This website lists several public opinion polls. Search the site and find a poll where the sample size and margin of error are given. Try to find a poll dealing with a topic in your profession or one in which you are really interested.
Main Post: Determine the following information for the selected poll results and include in your initial post. See Example I have attached.
- URL for the website. State the poll question, the sample size n, and the margin of error (also known as sampling error).
- Interpret the results of your poll using your own words and full sentences. Note: Depending on the question asked, your poll may have more than one poll result – you only need to discuss one result.
- State the confidence interval using the MoE. What does this confidence interval estimate?
- Use the Confidence Interval template (I have attached) to calculate the confidence interval based on the sample size and the number of successes (the proportion you are interested in). Use a confidence level of 95%.
- What is the calculated confidence interval? How does this compare to the interval in part 3 using the poll’s margin of error?
- Discuss potential biases that could skew sampling results.
1) Opinions about Hydraulic Fracturing (“fracking”) were surveyed nationally during March 2016. These survey results
can be found at: http://www.pollingreport.com/energy.htm
The question posed was “”Do you favor or oppose hydraulic fracturing or ‘fracking’ as a means of increasing the
production of natural gas and oil in the U.S.?”
Sample size, n =1,019 adults nationwide. Margin of error ± 4.
2) 36% were in favor of fracking as a method for increasing our energy resources in the US
51% were opposed of fracking as a method for increasing our energy resources in the US
13% were unsure of their opinion on fracking for increasing our energy resources in the US
3) The confidence interval for each result is found by adding/subtracting the MoE from the result.
In favor: (36 – 4%, 36 + 4%) = (32% – 40%)
4) & 5) Using the Excel template, I will enter the
Sample size = 1019
Proportion of sample = 36%
Confidence Level = 95%
Confidence Interval is (0.3304 – 0.3896) or
(33.04% – 38.96%)
6) I can imagine many biases that would affect the results of this survey. The first bias might be in the selection of
recipients of this survey. A selection bias might be present if the sample selection is not representative of the general
population. A sampling error might be present as well as is what the margin of error represents, for this case, 4%. We
do not know what organization sponsored the surveying process and analysis. If the sponsoring organization was a
fracking company, this could present an ethical question about the results. These are just a few considerations for
theses survey results.