# What is the direction of this scatterplot

QUESTION 1What is the direction of this scatterplot?positivenegative1 points QUESTION 2Before calculating the correlation coefficient, it is advisable to create a _____ as a way of displaying the association between the two variables.A.histogramB.scatterplotC.line graphD.polygon1 points QUESTION 3Order the scatterplots by strength from lowest to strongest.a)b)c) – 1. 2. 3. a – 1. 2. 3. b – 1. 2. 3. c1 points QUESTION 4A positive correlation between head size and foot size indicates that:A.people with larger feet tend to have smaller heads.B.people with larger feet also tend to have larger heads.C.having a large head causes a person to have large feet.D.having large feet causes a person to have a large head.1 points QUESTION 5In a reanalysis of published studies, Twenge and Im (2007) found that for the time period 1958–2001, the need for social approval of people in the United States was negatively correlated with the U.S. violent crime rate during the same period (the correlation coefficient was –0.31). This correlation means that:A.the need for social approval prevented people from committing violent crimes.B.the need for social approval spurred people to commit violent crimes.C.as the need for social approval went up, the number of violent crimes decreased.D.as the need for social approval went up, the number of violent crimes also increased.1 points QUESTION 6What is the null hypothesis when testing for significance using the Pearson correlation coefficient?A.r0B.? = 0C.?1 = ?2D.r = 01 points QUESTION 7What is the relationship between correlation and causation?A.Correlation is sufficient for causation.B.Correlation is both necessary and sufficient for causation.C.Correlation is necessary for causation.D.There is no relationship between correlation and causation.1 points QUESTION 8Which of these correlation coefficients allows a perfect prediction of scores on one variable from knowledge of scores on the other variable?A.0.50B.–1.00C.2.00D.01 points QUESTION 9The Pearson correlation coefficient is symbolized by:A.cB.tC.rD.x1 points QUESTION 10Which of these values indicates the strongest relationship between two variables?A.–0.72B.–0.25C.0.59D.0.651 points QUESTION 11If one wishes to assess the relation between a farming county’s average annual temperature and the crop yield, it may be important to take into account the overlapping variability that crop yield and temperature share with rainfall. To do so, one would compute a:A.partial correlation.B.coefficient alpha.C.concurrent validity.D.split-half reliability.1 points QUESTION 12Find the Mean Squared Between. The sample sizes for each of the groups is 28 and the sample means are as follows 22, 13, 17. Round tothe second decimal place if needed.1 points QUESTION 13If the F-statistic is not significant for a Within Subjects ANOVA, we should conduct follow up t-tests. True False1 points QUESTION 14If the sample sizes for each group is 28, and the sum of squares for each group is as follows: 3, 3, and 7, what is the Mean Squared Within? Round to the second decimal place, if needed.1 points QUESTION 15If the F-statistic is significant and you are comparing 3 sample means, what can you conclude?The mean for sample1 is different than the mean for sample 3.The mean for sample 2 is different than the mean for sample 3.The mean for sample 1 is different than the mean for sample 2.At least one of the sample means is different.1 points QUESTION 16You are conducting a dependent t-test: There is a repeated measure design and there is a pre and post test. What is the average of the difference scores?Your difference scores should be calculated like this: Difference = pre – post. Round to the second decimal place, if needed.prepost2791834989691 points QUESTION 17What number must the F-statistic be higher than to be significant?Note: Being greater than this number, does not guarantee it will be significant (depends on the degrees of freedom), but it must at least greater than this number to be significant.1 points QUESTION 18The _____ sum of squares is unique to the within-subjects design.A.subjectsB.totalC.between-groupsD.within-groups1 points QUESTION 19What is the correct formula for between-groups degrees of freedom?A.Ngroups – 1B.n – 2C.n – 1D.Ntotal – 11 points QUESTION 20The one-way within-groups design can be viewed as an extension of which other research design because of its ability to analyze data from more groups?A.paired-samples t testB.between-groups ANOVAC.independent-samples t testD.Tukey HSD test1 points QUESTION 21A researcher wants to examine people’s preference for pets by having 10 people act as “foster owners” for four different types of family pets: dogs, cats, birds, and fish. The participants will foster each type of pet for one week, and a scale measure will be used to assess preference. Which research design should be used?A.one-way within-groups ANOVAB.paired-samples t testsC.one-way between-groups ANOVAD.correlation1 points QUESTION 22A dependent-samples t test is used when there are _____ groups, and a within-groups ANOVA is used when there are at least _____ groups.A.2; 3B.3; 2C.1; 2D.1; 31 points QUESTION 23What is the degrees of freedom error for a Within Subjects ANOVA, if the number of time points is 3 and the number of subjects is 28?1 points QUESTION 24Suppose there is a repeated measure design. There are 4 time points and 3 subjects. The mean for subject 1 is 8, the mean for subject 2 is 8, and the mean for subject 3 is 7. What is the ? Hint: Find the grand mean first from the subject’s means. Make sure you take in account the number of time points. Round to the second decimal place if need.1 points QUESTION 25If the F-statistic is significant for a Within Subjects ANOVA, we should do what type of follow tests?CorrelationsChi-Square TestsIndependent t-testsDependent t-tests1 points QUESTION 26If the sample size is51 and the t-statistic is-2, what is the p-value fora greater than research hypothesis?.953893.984278.974526.9439211 points QUESTION 27If the is 85 and the is 15, what is the ?1 points QUESTION 28You are conducting an independent t-test to compare men and women on a performance test. If the standard deviation for men 6 for a sample of 45 and the standard deviation for women is 4 for a sample of 28, what is the pooled standard deviation? Round to the second decimal place as needed.1 points QUESTION 29If the is 62 and the is 30, what is the F-statistic? Round to the second decimal place, if needed.1 points QUESTION 30A professor is not sure which exam (1 or 2) that students do better on. The professor samples 10 students and records the exam 1 and exam 2 scores for each of the 10 students. Thus, there are 20 observations. What should the research hypothesis be? Assume that difference scores are calculated as such: difference = exam 2 – exam 1.1 points QUESTION 31A dependent t-test is used when your sample is paired. True False1 points QUESTION 32For an independent t-test: It is hypothesized that men score higher than women. What could be the research hypothesis?1 points QUESTION 33A professor believes that students in her class do better on the first test than on the second test. The professor samples 10 students and records the exam 1 and exam 2 scores for each of the 10 students. Thus, there are 20 observations. What should the research hypothesis be? Assume that difference scores are calculated as such: difference = exam 2 – exam 1.1 points QUESTION 34For an independent t-test: It is hypothesized that men score higher than women. What could be the research hypothesis?1 points QUESTION 35What would be the decision for the following paired-samples t test: t(24) = 1.11, p > 0.05?A.reject the null hypothesisB.reject the research hypothesisC.fail to reject the research hypothesisD.fail to reject the null hypothesis1 points QUESTION 36What is the mean difference of the following difference scores: –2, –19, +17, –22, –6?A.15.57B.6.96C.–0.92D.–6.401 points QUESTION 37A negatively skewed distribution would most likely violate which assumption?A.dependent variable is scaleB.random assignmentC.random selectionD.normality1 points QUESTION 38Twenty people participate in a weight-loss program for two months. Their weights after the two months are compared to their starting weights. What kind of mean difference might be expected if the null hypothesis is true for a paired-samples t test?A.no change in weight or weight gain, indicating that the program does not workB.weight loss, indicating that the program does not workC.a negative mean difference, indicating significant weight lossD.a loss of pounds, on average, showing the effectiveness of the program1 points QUESTION 39Assume the following for a paired-samples t test: N = 12, Mdifference = 635.65, s = 608.50. What is the t statistic?A.183.50B.3.62C.52.97D.1.041 points QUESTION 40What is the paired-samples t test for the following difference scores: 8, 3, 4.5, 7, 11.1, 9?A.2.97B.5.86C.1.21D.7.101 points QUESTION 41Assume the following for a paired-samples t test: N = 9, Mdifference = 13.19, s = 22.3. What is the t statistic?A.0.59B.7.43C.1.77D.4.401 points QUESTION 42For the following data, what is the mean of the difference scores?BeforeAfter110103981048997114127 A.8.52B.5.00C.1.17D.4.261 points QUESTION 43If the is 15, the is 9, and the is 8, what should the F-statistic be for a Within Subjects ANOVA? Round to the second decimal place, if needed. Hint: You only need 2 of the numbers for the calculation.1 points QUESTION 44As the variability of between-groups means increases, the F statistic decreases. True False1 points QUESTION 45Dr. Jameson wanted to know if IQ scores differed between male and female participants in his study. He gave 28 participants an IQ test and then compared IQ scores for gender differences. He hypothesized that there would be a statistically significant gender difference in IQ scores. Contrary to Dr. Jameson’s hypothesis, there were no differences in IQ scores between men and women in his study. Based on the information provided, does this study meet the assumption of normality? Why or why not?A.Yes; the population is likely to be normally distributed because the sample size is less than 30.B.We do not know whether it is normally distributed and the sample size is not at least 30 participants.C.Yes; it is normally distributed because the sample size is large.D.No; it is not normally distributed because the small sample size is small.1 points QUESTION 46Mehl (2007) published in the journal Science the results of an extensive study of 396 men and women comparing the number of words uttered per day by each sex. Which statistical test should Mehl use to analyze the data?A.z testB.single-sample t testC.independent-samples t testD.dependent-samples t test1 points QUESTION 47The results of an independent-samples t-test were t(18) = –2.11, p < 0.05. These results are:A.statistically significant.B.meaningful.C.not statistically significant.D.generalizable.1 points QUESTION 48Dr. Jameson wanted to know if IQ scores differed between male and female participants in his study. He gave 28 participants an IQ test and then compared IQ scores for gender differences. He hypothesized that there would be a statistically significant gender difference in IQ scores. Contrary to Dr. Jameson’s hypothesis, there were no differences in IQ scores between men and women in his study. From the results of the study, Dr. Jameson must _____ the null hypothesis and _____ the research hypothesis.A.retest; rejectB.reject; fail to rejectC.fail to reject; rejectD.reject; retest1 points QUESTION 49The statement “On average, older adults have the same response time as younger adults” is an example of:A.effect size.B.the null hypothesis.C.the research hypothesis.D.statistical significance.1 points QUESTION 50In a(n) _____, a within-groups design with two groups is used to compare the distribution of mean difference scores.A.z testB.independent-samples t testC.single-sample t testD.paired-samples t test