/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 24 Refer to the following story: Th... [FREE SOLUTION] | 91Ó°ÊÓ

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Refer to the following story: The 1250 students at Eureka High School are having an election for Homecoming King. The candidates are Tomlinson (captain of the football team), Garcia (class president), and Marsalis (member of the marching band). At the football game a week before the election, a pre- election poll was taken of students as they entered the stadium gates. Of the students who attended the game, 203 planned to vote for Tomlinson, 42 planned to vote for Garcia, and 105 planned to vote for Marsalis. (a) Give the sample statistics estimating the percentage of the vote going to each candidate. (b) A week after this survey, Garcia was elected Homecoming King with \(51 \%\) of the vote, Marsalis got \(30 \%\) of the vote, and Tomlinson came in last with \(19 \%\) of the vote. Find the sampling errors in the survey expressed as percentages.

Short Answer

Expert verified
The sample statistics estimating the percentage of the vote going to each candidate are as follows: Tomlinson - \(57.8\%\), Garcia - \(12\%\), and Marsalis - \(30\%\). The sampling errors in percentage are: Garcia - \(39\%\), Marsalis - \(0\%\), and Tomlinson - \(38.8\%\).

Step by step solution

01

Compute the Pre-election Vote Percentages

First, the total number of votes in the pre-election survey needs to be calculated. This is done by adding the results for each candidate together, which gives us \(203 + 42 + 105 = 350\). After that, the percentage of the total vote each candidate received is calculated individually. For instance, Tomlinson's percentage would be \(\frac{203}{350} \times 100\%\), Garcia's would be \(\frac{42}{350} \times 100\%\), and Marsalis' would be \(\frac{105}{350} \times 100\%\) respectively.
02

Record the Actual Vote Percentages

From the exercise, Garcia received \(51\%\) of the vote, Marsalis received \(30\%\) of the vote, and Tomlinson received \(19\%\) of the vote.
03

Calculate the Sampling Errors

The sampling error for each candidate is calculated by subtracting the pre-election vote percentage from the actual vote percentage. For instance, the sampling error for Garcia would be calculated as \(51\% - (percentage calculated in step 1)\). Similarly, the sampling errors for Marsalis and Tomlinson are calculated.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Sampling Error
When a sample does not perfectly represent the larger population, we encounter what is known as sampling error. This concept highlights the inherent limitations in using samples to draw conclusions about an entire group. In the election scenario at Eureka High School, the survey conducted at the football game was subject to sampling error because it attempted to predict the overall voting results based on a subset of the total student population.

The sampling error is the difference between what the poll predicted and the actual election results. This error occurs due to various factors, such as the sample not being large enough or not being representative of the entire population. In our example, if the sample primarily consisted of football fans, this might have skewed the results in favor of the football team captain, Tomlinson.
  • The predicted vote percentage for each candidate was calculated based on survey data.
  • To find each candidate's sampling error, subtract the predicted percentage from the actual election results.
Understanding sampling error is crucial for interpreting poll results accurately, especially in tight races like elections.
Vote Percentage Estimation
Estimating vote percentages involves predicting how a group, such as a student body, will vote based on a sample. This process is key to understanding potential outcomes in elections. Here, we determine the percentage of votes each candidate is expected to win by analyzing a sample.

In the Eureka High School election, a total of 350 students were surveyed at a football game. Each candidate's percentage estimate was calculated by dividing the number of votes each received by the total number of surveyed votes, then multiplying by 100 to express it as a percentage.
  • Tomlinson: Calculated by \(\frac{203}{350} \times 100\%\)
  • Garcia: Calculated by \(\frac{42}{350} \times 100\%\)
  • Marsalis: Calculated by \(\frac{105}{350} \times 100\%\)
Estimation helps identify trends and potential outcomes. However, as seen in this exercise, estimations can vary considerably from actual results due to factors that were not accounted for in the sample.
Pre-election Poll Analysis
Pre-election polls aim to gauge voter sentiment before the actual voting takes place. They serve as early indicators of how people may vote, and they are pivotal in formulating campaign strategies. However, interpreting these polls requires caution and an understanding of their limitations.

The pre-election poll conducted at Eureka High had several implications. First, it attempted to predict the voting outcome but highlighted potential biases, such as location bias, since it was conducted at a stadium where football fans are prevalent. Secondly, this poll underestimated Garcia's appeal and overestimated Tomlinson's support.

To conduct a robust pre-election poll:
  • Ensure the sample is representative of the entire population.
  • Avoid biases by selecting diverse survey locations.
  • Use past data to adjust and anticipate potential discrepancies.
Pre-election polls are an essential tool in elections, though interpreting their results should always consider the context and possible errors, as demonstrated with Garcia winning with a higher percentage than predicted.

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Most popular questions from this chapter

Refer to the following story (see also Exercise 32): The Dean of Students at Tasmania State University wants to determine how many undergraduates at TSU are familiar with a new financial aid program offered by the university. There are 15,000 undergraduates at \(T S U,\) so it is too expensive to conduct a census. The following sampling method, known as systematic sampling, is used to choose a representative sample of undergraduates to poll. Start with the registrar's alphabetical listing containing the names of all undergraduates. Randomly pick a number between 1 and \(100,\) and count that far down the list. Take that name and every 100 th name after it. For example, if the random number chosen is \(73,\) then pick the \(73 \mathrm{rd}, 173 \mathrm{rd}, 273 \mathrm{rd},\) and so forth, names on the list. (a) Find the sampling proportion. (b) Suppose that the survey had a response rate of \(90 \%\). Find the size \(n\) of the sample.

Refer to a study conducted between 2008 and 2010 on the effectiveness of saw palmetto fruit extracts at treating lower urinary tract symptoms in men with prostate enlargement. (Saw palmetto is a widely used over-the-counter supplement for treating urinary tract symptoms.) In the study, 369 men aged 45 years or older were randomly divided into a group taking a daily placebo and a group taking saw palmetto. Participants were nonpaid volunteers recruited at 11 North American sites. All had moderately impaired urinary flow. Because the saw palmetto extract has a mild odor, the doses were administered using gelcaps to eliminate the odor. In an analysis of the 306 men who completed the 72 -week trial, both groups had similar small improvements in mean symptom scores, but saw palmetto conferred no benefit over placebo on symptom scores or on any secondary outcomes. If you were a 55 -year-old male with an enlarged prostate taking saw palmetto daily, how might you react to this study?

Refer to a clinical study conducted at the Houston Veterans Administration Medical Center on the effectiveness of knee surgery to cure degenerative arthritis (osteoarthritis) of the knee. Of the 324 individuals who met the inclusion criteria for the study, 144 declined to participate. The researchers randomly divided the remaining 180 subjects into three groups: One group received a type of arthroscopic knee surgery called debridement; a second group received a type of arthroscopic knee surgery called lavage; and a third group received skin incisions to make it look like they had had arthroscopic knee surgery, but no actual surgery was performed. The patients in the study did not know which group they were in and in particular did not know if they were receiving the real surgery or simulated surgery. All the patients who participated in the study were evaluated for two years after the procedure. In the two-year follow-up, all three groups said that they had slightly less pain and better knee movement, but the "fake" surgery group often reported the best results. (a) Was the sample chosen by random sampling? Explain. (b) Was this study a controlled placebo experiment? Explain.

Refer to a clinical trial named APPROVe designed to determine whether Vioxx, a medication used for \(a r\) thritis and acute pain, was effective in preventing the recurrence of colorectal polyps in patients with a history of colorectal adenomas. APPROVe was conducted between 2002 and 2003 and involved 2586 participants, all of whom had a history of colorectal adenomas. The participants were randomly divided into two groups: 1287 were given 25 milligrams of Vioxx daily for the duration of the clinical trial (originally intended to last three years), and 1299 patients were given a placebo. Neither the participants nor the doctors involved in the clinical trial knew who was in which group. During the trial, 72 of the participants had cardiovascular events (mostly heart attacks or strokes). Later it was found that 46 of these people were from the group taking the Vioxx and only 26 were from the group taking the placebo. Based on these results, the clinical trial was stopped in 2003 and Vioxx was taken off the market in 2004. (a) Describe the control and treatment groups in APPROVe. (b) APPROVe can be described as a double-blind, randomized controlled placebo study. Explain why each of these terms applies.

Starting in \(2004,\) a study to determine the number of lake sturgeon on Rainy River and Lake of the Woods on the United States-Canada border was conducted by the Canadian Ministry of Natural 91Ó°ÊÓ, the Minnesota Department of Natural 91Ó°ÊÓ, and the Rainy River First Nations. Using the capture- recapture method, the size of the population of lake sturgeon on Rainy River and Lake of the Woods was estimated at \(N=160,286\). In the capture phase of the study, 1700 lake sturgeon were caught, tagged, and released. Of these tagged sturgeon, seven were recaptured during the recapture phase of the study. Based on these figures, estimate the number of sturgeon caught in the recapture phase of the study. [Source: Dan Gauthier, "Lake of the Woods Sturgeon Population Recovering," Daily Miner and News (Kenora, Ont.), June \(11,2005,\) p. 31.]

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