/*! 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 22 Use the following information to... [FREE SOLUTION] | 91影视

91影视

Use the following information to answer the next seven exercises: Studies are often done by pharmaceutical companies to determine the effectiveness of a treatment program. Suppose that a new AIDS antibody drug is currently under study. It is given to patients once the AIDS symptoms have revealed themselves. Of interest is the average (mean) length of time in months patients live once starting the treatment. Two researchers each follow a different set of 40 AIDS patients from the start of treatment until their deaths. The following data (in months) are collected. Researcher A: 3; 4; 11; 15; 16; 17; 22; 44; 37; 16; 14; 24; 25; 15; 26; 27; 33; 29; 35; 44; 13; 21; 22; 10; 12; 8; 40; 32; 26; 27; 31; 34; 29; 17; 8; 24; 18; 47; 33; 34 Researcher B: 3; 14; 11; 5; 16; 17; 28; 41; 31; 18; 14; 14; 26; 25; 21; 22; 31; 2; 35; 44; 23; 21; 21; 16; 12; 18; 41; 22; 16; 25; 33; 34; 29; 13; 18; 24; 23; 42; 33; 29 Suppose that the first researcher conducted his survey by randomly choosing one state in the nation and then randomly picking 40 patients from that state. What sampling method would that researcher have used?

Short Answer

Expert verified
The researcher used cluster sampling.

Step by step solution

01

Understanding Sampling Methods

In statistics, there are several sampling methods, such as simple random sampling, stratified sampling, cluster sampling, and systematic sampling. The method used depends on how the sample is collected from the population.
02

Defining the Given Scenario

Researcher A randomly selects one state from the nation and then, within that state, randomly selects 40 patients for the study. This approach to sampling involves two stages: choosing a state and then choosing individuals within that state.
03

Identifying the Method

In this scenario, the selection starts with a larger grouping (states) before breaking down to the individual level (patients), which indicates that cluster sampling is being used. In cluster sampling, a researcher divides the population into clusters (states, in this scenario) and then randomly selects some clusters for further sampling at the individual level. This differs from stratified sampling, where samples are collected from each subgroup of the population.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

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

Sampling Methods
Sampling methods play a crucial role in the design of any study. They determine how participants or subjects are chosen from a larger group. Here are some of the common sampling methods you might encounter:
  • Simple Random Sampling: Every member of the population has an equal chance of being selected. This method ensures unbiased representation but can be challenging with large populations.
  • Stratified Sampling: The population is divided into distinct subgroups, and samples are taken from each group. This ensures representation across all subgroups.
  • Cluster Sampling: The population is divided into clusters, usually geographically or by a specific characteristic. Entire clusters are then randomly selected for the study. This method is often more practical for large populations.
  • Systematic Sampling: Samples are selected at regular intervals from an ordered population list. For example, choosing every 10th name in a phone book.
Understanding these methods helps researchers choose the best approach for their specific study, ensuring accurate and reliable outcomes. In our scenario, Researcher A chose cluster sampling by selecting an entire state before picking individuals, making it a practical choice given logistical constraints.
Pharmaceutical Studies
Pharmaceutical studies are integral in developing, testing, and approving new drugs. These studies require meticulous design to ensure they yield reliable and valid results. Here's why they're significant:
  • Drug Efficacy: A primary goal is to determine how effective a new drug is. This is done by measuring specific outcomes, such as the average time a patient lives after starting treatment, as in our example.
  • Safety Assessment: Assessing side effects and ensuring that the benefits of a drug outweigh any risks is crucial before a drug can be approved and brought to market.
  • Regulatory Compliance: Studies must adhere to strict regulations and protocols to ensure ethical standards are upheld. This includes obtaining informed consent from participants and maintaining transparency throughout the study.
Choosing the right sampling method is vital in these studies. It impacts the representativeness and generalizability of the study findings. In our case, cluster sampling was a beneficial choice for practical reasons, facilitating manageable data collection while still aiming for meaningful insights.
Statistical Analysis
Statistical analysis is the backbone of interpreting data in any research study. Its purpose is to make sense of the collected data, often leading to conclusions about the effectiveness or impact of certain treatments. Here are some key elements:
  • Descriptive Statistics: These stats summarize the data, providing measures like mean, median, mode, and standard deviation. In our AIDS study, the focus is on the mean survival time post-treatment.
  • Inferential Statistics: This involves making predictions or inferences about a population based on sample data. Techniques like hypothesis testing and confidence intervals fall under this category.
  • Comparative Analysis: Sometimes, studies compare different groups or conditions. For instance, comparing the survival times of patients under different treatments.
In our study of the AIDS treatment, statistical analysis is crucial for determining how the new drug affects patient survival times. Accurate analysis helps in evaluating the true potential of the treatment and guiding future research efforts.
AIDS Treatment Study
An AIDS treatment study aims to assess the effectiveness of a new drug or treatment protocol. These studies are vital in the ongoing battle against AIDS, focusing on improving patients' quality and duration of life. Key aspects include:
  • Focus on Outcomes: The primary interest is often on outcomes like survival time, quality of life, or reduction in symptoms, providing evidence of the treatment's effectiveness.
  • Patient Selection: Carefully selecting participants is essential. Researchers need diverse participants to ensure findings are broadly applicable. Cluster sampling, like in our example, provides a practical means of achieving this.
  • Monitoring and Evaluation: Continuous monitoring of patient progress and rigorous evaluation of the collected data are necessary to draw valid conclusions about the treatment's impact.
Through these studies, researchers aim to enhance treatment protocols, offering more effective solutions for AIDS patients and contributing to the broader medical knowledge on the disease. The process is iterative, often leading to improvements in both drug formulations and study methodologies.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A question on a survey reads: "Do you prefer the delicious taste of Brand \(X\) or the taste of Brand \(Y?\)" Is this a fair question?

Determine the type of sampling used (simple random, stratified, systematic, cluster, or convenience). The first 50 people who walk into a sporting event are polled on their television preferences.

In advance of the 1936 Presidential Election, a magazine titled Literary Digest released the results of an opinion poll predicting that the republican candidate Alf Landon would win by a large margin. The magazine sent post cards to approximately 10,000,000 prospective voters. These prospective voters were selected from the subscription list of the magazine, from automobile registration lists, from phone lists, and from club membership lists. Approximately 2,300,000 people returned the postcards. a. Think about the state of the United States in 1936. Explain why a sample chosen from magazine subscription lists, automobile registration lists, phone books, and club membership lists was not representative of the population of the United States at that time. b. What effect does the low response rate have on the reliability of the sample? c. Are these problems examples of sampling error or non sampling error? d. During the same year, George Gallup conducted his own poll of 30,000 prospective voters. His researchers used a method they called "quota sampling" to obtain survey answers from specific subsets of the population. Quota sampling is an example of which sampling method described in this module?

For each of the following eight exercises, identify: a. the population, b. the sample, c. the parameter, d. the statistic, e. the variable, and f. the data. Give examples where appropriate. Political pollsters may be interested in the proportion of people who will vote for a particular cause.

鈥淣umber of times per week鈥 is what type of data? a. qualitative b. quantitative discrete c. quantitative continuous

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.