교과서 질문
In Exercises 13–20, determine whether the data are from a discrete or continuous data set.
Statistics Classes In each of her classes, a statistics professor records the number of students who earned a grade of A.
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Ch. 1 - Introduction to Statistics
Triola14th EditionElementary StatisticsISBN: 9780137366446
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Table of contents
- Ch. 1 - Introduction to Statistics88
- Ch. 2 - Exploring Data with Tables and Graphs70
- Ch. 3 - Describing, Exploring, and Comparing Data66
- Ch. 4 - Probability112
- Ch. 5 - Discrete Probability Distributions109
- Ch. 6 - Normal Probability Distributions122
- Ch. 7 - Estimating Parameters and Determining Sample Sizes107
- Ch. 8 - Hypothesis Testing75
- Ch. 9 - Inferences from Two Samples94
- Ch. 10 - Correlation and Regression80
- Ch. 11 - Goodness-of-Fit and Contingency Tables29
- Ch. 12 - Analysis of Variance42
1장, 문제 1.3.31
In Exercises 29–32, indicate whether the observational study used is cross-sectional, retrospective, or prospective.
Marijuana Study Researchers from the National Institutes of Health want to determine the current rates of marijuana consumption among adults living in states that have legalized the use of marijuana. They conduct a survey of 500 adults in those states.
검증된 단계별 안내1
Understand the types of observational studies: Cross-sectional studies collect data at a single point in time, retrospective studies look back at past data, and prospective studies follow subjects into the future.
Identify the key elements of the study: The researchers are conducting a survey to determine current rates of marijuana consumption among adults.
Determine the timing of data collection: Since the study involves collecting data at a single point in time to assess current consumption rates, it is not looking at past data or following subjects into the future.
Classify the study based on the timing: Given that the data is collected at one point in time to understand the current situation, this study is a cross-sectional study.
Conclude with the study type: The observational study used in this scenario is cross-sectional because it assesses the current state of marijuana consumption among adults in states where it is legalized.
비슷한 문제에 대한 검증된 영상 답변:
이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m도움이 되었나요?
주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
Observational Study
An observational study is a research method where the investigator observes subjects and measures variables of interest without assigning treatments to the subjects. The goal is to find associations between variables, and it is often used when experiments are not feasible or ethical. This type of study can be cross-sectional, retrospective, or prospective.
추천 영상:
가이드 코스
04:39
Visualizing Qualitative vs. Quantitative Data
Cross-Sectional Study
A cross-sectional study is a type of observational study that analyzes data from a population, or a representative subset, at a specific point in time. It is often used to assess the prevalence of an outcome or to identify associations between variables. In the context of the marijuana study, the survey of 500 adults provides a snapshot of current marijuana consumption rates.
추천 영상:
가이드 코스
03:26Calculating the Median
Prospective vs. Retrospective Study
Prospective studies follow participants over a future period to observe outcomes, while retrospective studies look back at existing data or past events. In the marijuana study, the researchers are interested in current consumption rates, indicating a cross-sectional approach rather than a prospective or retrospective one, as they are not following participants over time or examining past data.
추천 영상:
가이드 코스
04:39Visualizing Qualitative vs. Quantitative Data
관련 실천
교과서 질문
In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.
Criminology Researchers randomly selected 50 convicted felons from each category of burglary, auto theft, and assault.
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교과서 질문
In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.
Highway Strength The New York State Department of Transportation evaluated the quality of the New York State Thruway by testing core samples collected at regular intervals of 1 mile.
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교과서 질문
In Exercises 33–36, identify which of these designs is most appropriate for the given experiment: completely randomized design, randomized block design, or matched pairs design.
West Nile Vaccine Currently, there is no approved vaccine for the prevention of infection by West Nile virus. A clinical trial of a possible vaccine is being planned to include subjects treated with the vaccine while other subjects are given a placebo.
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교과서 질문
In Exercises 5–12, identify whether the given value is a statistic or a parameter.
Drivers According to the Federal Highway Administration, there are 212 million licensed drivers in the United States.
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교과서 질문
In Exercises 13–20, determine whether the results appear to have statistical significance, and also determine whether the results appear to have practical significance.
Election Fraud The County Clerk in Essex County, New Jersey, was responsible for randomly assigning the order in which candidates’ names appeared on a recent election ballot. Among 41 different ballots, a Democrat was placed on the first line 40 times, and a Republican was placed on the first line once.
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