Solutions-Chapter 1-page281Chapter 1: Introduction to Statistics1.a. The population is the entire set of adolescent boys who are taking medication fordepression.b. The sample is the group of 30 boys who were tested in the study.2.A parameter is a characteristic, usually a numerical value, that describes a population. Astatistic is a characteristic, usually numerical, that describes a sample.3Descriptive statistics are used to simplify and summarize data. Inferential statistics usesample data to make general conclusions about populations.4. a. If treatments 1 and 2 affect individuals differently, then the scores in the first sample willbe different from the scores in the second sample.b. Even if the two treatments have exactly the same effect, you do not expect the individualsin one condition to behave exactly the same as the individuals in the other treatment. Thetwo groups will produce different scores with different means. In this case, the differencesare the result of sampling error.5. A correlational studyhas only one group of individuals andmeasures two(or more)differentvariables for each individual. Other research methods evaluating relationships between variablescompare two (or more) different groups of scores.6. The goal of an experiment is to demonstrate the existence of a cause-and-effect relationshipbetween two variables. To accomplish the goal, an experiment must manipulate an independentvariable and control other, extraneous variables.7. The independent variable is holding a pen in your teeth versus holding the pen in your lips.The dependent variable is the rating given to each cartoon.8. This is not an experiment because no independent variable is manipulated. They arecomparing two preexisting groups of individuals.9. a. This is a nonexperimental study. The researcher is simply observing, not manipulating,two variables.b. This is an experiment. The researcher is manipulating the type of drink and should controlother variables by beginning with equivalent groups of participants.10.a. The dependent variable is the number of colds each participant has during the winter.b. discretec. ratio scale (zero means none)Preview Mode
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