Mr. Ellis: Exam Review III – Flashcards
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When the point in a scatter plot cluster closely around the regression line, the correlation can be
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strong.
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In a hypothesis test, which of the following will cause a decrease in B, the probability of making a type II error?
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A: increasing x while keeping the sample size n, fixed B: Increasing the sample size n, while keeping x fixed A and B
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The owner of a football team claims that the average attendance at games is over 70,400, and he is therefore justified in moving the team to a city with a larger stadium. Identify the type II error for the test.
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The error of failing to reject the claim that the mean attendance is at most 70,400, when it is actually greater than 70,400.
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The principal of a middle school claims that test scores of the seventh-graders at his school vary less than the test scores of the seventh-graders at a neighboring school, which have variation described by x=14.7. Identify the type I error for the test.
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The error of rejecting the claim that the standard deviation is less than 14.7 when it really is less than 14.7.
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The variable being predicted in a regression analysis is called the:
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dependent variable
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a researcher claims that the amounts of acetaminophen in a certain brand of cold tablets have a standard deviation different from the o= 3.3 mg claimed by the manufacturer. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, state the conclusion in nontechnical terms.
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There is not sufficient evidence to support the claim that the standard deviation is different from 3.3mg.
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A cereal company claims that the mean weight of the cereal in its packets is at least 14 oz. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is to reject the null hypothesis, state the conclusion in nontechnical terms.
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There is sufficient evidence to warrant rejection of the claim that the mean weight is at least 14 oz.
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In what section of a research article should the authors describe each analysis in a systematic fashion?
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methods
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When conducting a t test for independent means, a typical research hypothesis might be
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the mean of Population 1 is greater than the mean of Population 2
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a researcher claims that the amounts of acetaminophen in a certain brand of cold tablets have a standard deviation different from the o= 3.3 mg claimed by the manufacturer.
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Ho: o ==3.3mg Ha: o =/= 3.3mg
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a researcher claims that 62% of voters favor gun control.
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Ho: p ==0.62 Ha: p =/=0.62
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Before embarking on a new study, experienced researchers plan what statistical method(s) they will use when the study is complete. Why is it important to carry out this step?
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all of the above
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The set of frequencies obtained in an actual frequency distribution are the:
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observed frequencies
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The variation observed between group means is referred to as:
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between group variation.
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a regression line
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shows the relation between values of the predictor and criterion variables.
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Before running statistical analyses, researchers should check their data for:
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all of the above
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A chi-square test of significance is essentially concerned with:
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the distinction between expected and observed frequencies.
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The variation found among raw scores in a particular group is referred to as:
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within group variation.
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Once a researcher has an idea for a research question, the next step is to:
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develop a specific research plan to address the question
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Parametric tests require:
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a normal distribution
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In the Discussion section of a research article, one should:
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all of the above
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An analysis of variance differs from a t test for independent means in that an analysis of variance
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can be used to compare three or more groups, while a t test for independent means cannot be used to compare more than two groups.
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In a one-way analysis of variance with three groups, the null hypothesis states:
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at least two of the groups differ
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Regression analysis creates a mathematical function which predicts the value of the _______ on the basis of the __________________.
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dependent variable; independent variable
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Expected frequencies represent:
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the frequencies one would expect if the null hypothesis were true.
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In a regression analysis
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one variable is believed to be influenced by the other.
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A researcher takes a sample and wants to compare the results to the population from which it was drawn. The independent variable is "gender" and the dependent variable is a yes/no response to whether they favor the abortion. Which test would the researcher use to see if results are significant?
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a difference between means test
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Which of the following is the best way to reduce the variances in the distributions of means when conducting a t test for independent means?
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increasing the size of the samples
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Which of the following is not a component of the regression equation?
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error
