/*! 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} Q. 66 Killing weeds A biologist would ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Q. 66 (page 265)

Killing weeds A biologist would like to determine which of two brands of weed killer, X or Y, is less likely to harm the plants in a garden at the university. Before spraying near the plants, the biologist decides to conduct an experiment using24individual plants. Which of the following two plans for randomly assigning the treatments should the biologist use? Why?

Plan A: Choose the12healthiest-looking plants. Then flip a coin. If it lands heads, apply Brand X weed killer to these plants and Brand Y weed killer to the remaining12plants. If it lands tails, do the opposite.

Plan B: Choose12of the24plants at random. Apply Brand X weed killer to those12plants and Brand Y weed killer to the remaining12plants.

Short Answer

Expert verified

Plan B should be used because it follows the principle of random assignment.

Step by step solution

01

Given Information

We are given that the biologist wants to check whether from X or Y which will harm the plans, and that they have two plans, Plan A and Plan B, and we have to find out which plan is following random assignment.

02

Explanation

According to the question, a biologist has to choose the plan that follows random assignment. Random assignment means that the particular should be choose randomly but in Plan A twelve plants are choose by seeing their healthiness which means randomization is not present here while in Plan B all twenty four plants are taken and twelve are given X weed while other are given Y weed which means randomly plants are chosen.

Hence, Plan B is the correct way.

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!

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

Corn variety 1yielded 140bushels per acre last year at a research farm. This year, corn

variety 2, planted in the same location, yielded only 110bushels per acre. Based on these

results, is it reasonable to conclude that corn variety 1is more productive than corn variety

2?

a. Yes, because 140bushels per acre is greater than 110bushels per acre.

b. Yes, because the study was done at a research farm.

c. No, because there may be other differences between the two years besides the corn

variety.

d. No, because there was no use of a placebo in the experiment.

e. No, because the experiment wasn鈥檛 double-blind.

Reporting weight loss A total of 300 people participated in a free 12-week weight-loss

course at a community health clinic. After one year, administrators emailed each of the

300 participants to see how much weight they had lost since the end of the course. Only

56 participants responded to the survey. The mean weight loss for this sample was 13.6

pounds. Describe how nonresponse might lead to bias in this study. Explain the likely

direction of the bias.

Precise offers People often use round prices as first offers in a negotiation. But would a more precise number suggest that the offer was more reasoned and informed? In an experiment, 238adults played the role of a person selling a used car. Each adult received one of three initial offers: \(2000, \)1865(a precise under-offer), and \(2135(a precise over-offer). After hearing the initial offer, each subject made a counter-offer. The difference in the initial offer and counter-offer was the largest in the group that received the \)2000 offer. Describe how the researchers could have randomly assigned the subjects to the treatments

a. using slips of paper.

b. using technology.

c. using Table D.

A popular website places opinion poll questions next to many of its news stories. Simply

click your response to join the sample. One of the questions was 鈥淒o you plan to diet this

year?鈥� More than 30,000 people responded, with 68% saying 鈥淵es.鈥� Which of the

following is true?

a. About 68% of Americans planned to diet.

b. The poll used a convenience sample, so the results tell us little about the population of

all adults.

c. The poll uses voluntary response, so the results tell us little about the population of all

adults.

d. The sample is too small to draw any conclusion.

e. None of these.

SRS of engineers? A corporation employs 2000 male and 500 female engineers. A stratified random sample of 200 male and 50 female engineers gives every individual in the population the same chance to be chosen for the sample. Is it an SRS? Explain your answer.
See all solutions

Recommended explanations on Math Textbooks

Decision Maths

Read Explanation

Geometry

Read Explanation

Pure Maths

Read Explanation

Probability and Statistics

Read Explanation

Mechanics Maths

Read Explanation

Logic and Functions

Read Explanation
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.