Research Methods for the Behavioral Sciences (MindTap Course List)
5th Edition
ISBN: 9781305104136
Author: Frederick J Gravetter, Lori-Ann B. Forzano
Publisher: Wadsworth Publishing
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Chapter 7, Problem 2EA
A researcher examines the relationship between the quality of breakfast and academic performance for a group of elementary-school children. For each child, the researcher interviews the parents to obtain information about the child’s typical breakfast, and uses school records to obtain a measure of academic performance.
- Explain why this study is not a true experiment.
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Chapter 7 Solutions
Research Methods for the Behavioral Sciences (MindTap Course List)
Ch. 7.1 - Describe the general purpose of an experimental...Ch. 7.1 - Define independent, dependent, and extraneous...Ch. 7.1 - Describe the third-variable problem and the...Ch. 7.2 - Explain why manipulation of an independent...Ch. 7.2 - Explain why control of extraneous variables is a...Ch. 7.2 - Explain how an extraneous variable can become a...Ch. 7.3 - Describe the three primary techniques for...Ch. 7.4 - Describe the purpose for control conditions in...Ch. 7.4 - Explain when a manipulation check is needed,...Ch. 7.5 - Define field studies and simulation, explain why...
Ch. 7 - In addition to the key words, you should also be...Ch. 7 - Dr. Jones conducted a study examining the...Ch. 7 - In an experiment examining human memory, two...Ch. 7 - It has been demonstrated that students with high...Ch. 7 - A researcher would like to compare two methods for...Ch. 7 - Define extraneous variable and explain how...Ch. 7 - Identify the two characteristics needed for a...Ch. 7 - Identify the two active methods of preventing...Ch. 7 - Explain how the process of randomly assigning...Ch. 7 - Can a research study be an experiment without a...Ch. 7 - What is the general purpose of a manipulation...Ch. 7 - What is the general purpose for using a simulation...Ch. 7 - Prob. 1EACh. 7 - A researcher examines the relationship between the...
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- 26. A certain system can experience three different types of defects. Let A;(i = 1,2,3) denote the event that the sys- tem has a defect of type i. Suppose thatP(A1) = .12 P(A) = .07 P(A) = .05P(A, U A2) = .13P(A, U A3) = .14P(A2 U A3) = .10P(A, A2 A3) = .011Rshelfa. What is the probability that the system does not havea type 1 defect?b. What is the probability that the system has both type 1 and type 2 defects?c. What is the probability that the system has both type 1 and type 2 defects but not a type 3 defect? d. What is the probability that the system has at most two of these defects?arrow_forwardThe following are suggested designs for group sequential studies. Using PROCSEQDESIGN, provide the following for the design O’Brien Fleming and Pocock.• The critical boundary values for each analysis of the data• The expected sample sizes at each interim analysisAssume the standardized Z score method for calculating boundaries.Investigators are evaluating the success rate of a novel drug for treating a certain type ofbacterial wound infection. Since no existing treatment exists, they have planned a one-armstudy. They wish to test whether the success rate of the drug is better than 50%, whichthey have defined as the null success rate. Preliminary testing has estimated the successrate of the drug at 55%. The investigators are eager to get the drug into production andwould like to plan for 9 interim analyses (10 analyzes in total) of the data. Assume thesignificance level is 5% and power is 90%.Besides, draw a combined boundary plot (OBF, POC, and HP)arrow_forwardPlease provide the solution for the attached image in detailed.arrow_forward
- 20 km, because GISS Worksheet 10 Jesse runs a small business selling and delivering mealie meal to the spaza shops. He charges a fixed rate of R80, 00 for delivery and then R15, 50 for each packet of mealle meal he delivers. The table below helps him to calculate what to charge his customers. 10 20 30 40 50 Packets of mealie meal (m) Total costs in Rands 80 235 390 545 700 855 (c) 10.1. Define the following terms: 10.1.1. Independent Variables 10.1.2. Dependent Variables 10.2. 10.3. 10.4. 10.5. Determine the independent and dependent variables. Are the variables in this scenario discrete or continuous values? Explain What shape do you expect the graph to be? Why? Draw a graph on the graph provided to represent the information in the table above. TOTAL COST OF PACKETS OF MEALIE MEAL 900 800 700 600 COST (R) 500 400 300 200 100 0 10 20 30 40 60 NUMBER OF PACKETS OF MEALIE MEALarrow_forwardLet X be a random variable with support SX = {−3, 0.5, 3, −2.5, 3.5}. Part ofits probability mass function (PMF) is given bypX(−3) = 0.15, pX(−2.5) = 0.3, pX(3) = 0.2, pX(3.5) = 0.15.(a) Find pX(0.5).(b) Find the cumulative distribution function (CDF), FX(x), of X.1(c) Sketch the graph of FX(x).arrow_forwardA well-known company predominantly makes flat pack furniture for students. Variability with the automated machinery means the wood components are cut with a standard deviation in length of 0.45 mm. After they are cut the components are measured. If their length is more than 1.2 mm from the required length, the components are rejected. a) Calculate the percentage of components that get rejected. b) In a manufacturing run of 1000 units, how many are expected to be rejected? c) The company wishes to install more accurate equipment in order to reduce the rejection rate by one-half, using the same ±1.2mm rejection criterion. Calculate the maximum acceptable standard deviation of the new process.arrow_forward
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