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Ch. 7 - Estimating Parameters and Determining Sample Sizes
Triola - Elementary Statistics 14th Edition
Triola14th EditionElementary StatisticsISBN: 9780137366446당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Triola 14th EditionCh. 7 - Estimating Parameters and Determining Sample Sizes문제 7.3a
7장, 문제 7.3a

Voting Survey In a survey of 1002 people, 70% said that they voted in a recent presidential election (based on data from ICR Research Group). Voting records show that 61% of eligible voters actually did vote.


a. Among the 1002 people surveyed, what is the actual number of people who said that they voted?

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Step 1: Identify the total number of people surveyed, which is given as 1002.
Step 2: Note that 70% of the surveyed people said they voted. Convert this percentage to a decimal by dividing by 100, which gives 0.70.
Step 3: To find the actual number of people who said they voted, multiply the total number of surveyed people (1002) by the decimal representation of the percentage (0.70).
Step 4: Use the formula: \( \text{Number of people who said they voted} = 1002 \times 0.70 \).
Step 5: Perform the multiplication to determine the result, which represents the number of people who claimed they voted in the survey.

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Percentage Calculation

Percentage calculation is a mathematical process used to determine a portion of a whole. In this context, to find the actual number of people who said they voted, you multiply the total number of surveyed individuals (1002) by the percentage of those who claimed to have voted (70%). This results in a straightforward calculation that helps quantify survey responses.
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Survey Sampling

Survey sampling involves selecting a subset of individuals from a larger population to estimate characteristics of the whole group. In this case, the 1002 surveyed individuals represent a sample from the broader population of eligible voters. Understanding sampling is crucial for interpreting survey results and assessing their reliability and validity.
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Sampling Distribution of Sample Proportion

Voter Turnout

Voter turnout refers to the percentage of eligible voters who actually cast a ballot in an election. The survey indicates that 70% of respondents claimed to have voted, while official records show that only 61% of eligible voters participated. This discrepancy highlights the importance of distinguishing between self-reported voting behavior and actual voting records, which can inform discussions about electoral engagement.
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a. Assume that nothing is known about the percentage of passengers who prefer aisle seats.


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a. Assume that nothing is known about the percentage to be estimated.


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