In the t test for independent groups, ____. we estimate µ1 µ2 we estimate 2 we estimate X1-X2 df = N 1 Exhibit 14-1 A professor of women's studies is interested in determining if stress affects the menstrual cycle. Ten women are randomly sampled for an experiment and randomly divided into two groups. One of the groups is subjected to high stress for two months while the other lives in a relatively stress-free environment. The professor measures the menstrual cycle (in days) of each woman during the second month. The following data are obtained. High stress 20 23 18 19 22 Relatively stress free 26 31 25 26 30 Refer to Exhibit 14-1. The obtained value of the appropriate statistic is ____. tobt = 4.73 tobt = 4.71 tobt = 3.05 tobt = 0.47 Refer to Exhibit 14-1. The df for determining tcrit are ____. 4 9 8 3 Refer to Exhibit 14-1. Using = .052 tail, tcrit = ____. +2.162 +2.506 ±2.462 ±2.306 Refer to Exhibit 14-1. Using = .052 tail, your conclusion is ____. accept H0; stress does not affect the menstrual cycle retain H0; we cannot conclude that stress affects the menstrual cycle retain H0; stress affects the menstrual cycle reject H0; stress affects the menstrual cycle Refer to Exhibit 14-1. Estimate the size of the effect. = ____ 0.8102 0.6810 0.4322 0.5776 A major advantage to using a two condition experiment (e.g. control and experimental groups) is ____. the test has more power the data are easier to analyze the experiment does not need to know population parameters the test has less power Which of the following tests analyzes the difference between the means of two independent samples? correlated t test t test for independent groups sign test test of variance If n1 = n2 and n is relatively large, then the t test is relatively robust against ____. violations of the assumptions of homogeneity of variance and normality violations of random samples traffic violations violations by the forces of evil Exhibit 14-3 Five students were tested before and after taking a class to improve their study habits. They were given articles to read which contained a known number of facts in each story. After the story each student listed as many facts as he/she could recall. The following data was recorded. Before 10 12 14 16 12 After 15 14 17 17 20 Refer to Exhibit 14-3. The obtained value of the appropriate statistic is ____. 3.92 3.06 4.12 2.58 Refer to Exhibit 14-3. What do you conclude using = 0.052 tail? reject H0; the class appeared to improve study habits retain H0; the class had no effect on study habits retain H0; we cannot conclude that the class improved study habits accept H0; the class appeared to improve study habits Which of the following is (are) assumption(s) underlying the use of the F test? the raw score populations are normally distributed the variances of the raw score populations are the same the mean of the populations differ the raw score populations are normally distributed and the variances of the raw score populations are the same If its assumptions are met, the analysis of variance technique is appropriate when ____. two or more factors are varied several levels of a single independent variable are compared three or more groups are involved all of the other three options A major limitation of a two group design is that ____. we can't run enough subjects very often, two groups are insufficient for a clear interpretation the population parameters may not be applicable the means between groups may not differ sB2 is a measure of ____. 2 alone 2 + the effects of the independent variable the variability between the means 2 + the effects of the independent variable and the variability between the means The total degrees of freedom for an experiment with n1 = 10, n2 = 12, and n3 = 10 is ____. 2 32 31 29 Exhibit 15-3 Pertain to the following data. Refer to Exhibit 15-3. What is the value of Fobt? 5.67 6.53 1.95 3.26 Refer to Exhibit 15-3. What is the value of Fcrit ? Use = 0.05. 5.14 4.76 4.46 4.07 Refer to Exhibit 15-3. What is your conclusion? Again use = 0.05 retain H0 reject H1 reject H0 accept H0 Refer to Exhibit 15-3. Using , the estimated size of effect is ____. 22.6% of the variability 52.8% of the variability 43.6% of the variability 55.1% of the variability Refer to Exhibit 15-3. Using 2, what is the estimated size of effect? 0.7232 0.6852 0.6582 0.6312 What is the value of SST if SSB = 236 and SSW = 54? 290 182 4.37 100 By doing multiple t tests when there are more than 2 experimental groups we increase the risk of making what kind of mistake? accepting H0 Type I error Type II error all of the other three options If = 46, = 50, = 92 and n1 = n2 = n3, what is the value of ? cannot be determined from information given 50.0 188.0 62.67 If SSW = 126, N = 28, k = 4, then what is the value of sW2 cannot be determined from information given 5.25 42.0 4.667 If dfB = 3 and dfT = 29 and Fobt = 3.15, what would you conclude using = 0.05? reject H0 reject H1 retain H0 retain H1 If sB2 = 27.9 and sW2 = 54.2, what is the value of Fobt? impossible result, there must be an error 1.94 0.51 2.76 A priori comparisons ____. are planned in advance of the experiment often arise out of theory and prior research may be done without obtaining a significant Fobt in the one-way ANOVA all of the other three options Chi-square is used to test differences between ____. proportions means variances none of the other three options The sampling distribution of chi-square is ____. skewed varies with df is a theoretical distribution all of the other three options A contingency table ____. is a two-way table involves two variables involves two mutually exclusive variables is a two-way table and involves two variables The computation of fe ____. is based on population proportion estimates is based on known population proportions is based on population means none of the other three options If N = 18 and = 0.052 tailed, the value of Tcrit is ____. 40 39 41 47 If = 0.05, and df = 4, the value of 2crit = ____. 9.488 0.711 7.815 11.070 Exhibit 17-1 Prior to a recent gubernatorial election, a survey was conducted to determine whether there was a relationship between sexual gender and preference for the Democratic or Republican candidate. The following data were recorded. Refer to Exhibit 17-1. The value of 2obt = ____. 2.06 2.09 1.80 1.75 Refer to Exhibit 17-1. The value of df = ____. 2 1 3 need more information Refer to Exhibit 17-1. Using = 0.05, 2crit = ____. 3.841 5.412 2.706 3.841 Refer to Exhibit 17-1. Using = 0.05, what is your conclusion? accept H0; there is no relationship between sex and candidate preference reject H0; there is a significant relationship between sex and candidate preference retain H0; the study does not show a significant relationship between sex and candidate preference retain H0; this study shows a significant relationship between sex and candidate preference As the separation between the two groups of scores increases, Uobt ____. increases decreases stays the same approaches Uobt The statistics (U or U') used in the Mann-Whitney U test, measure ____. the differences between the means of the two groups the direction of the differences between pairs of scores the power of the experiment the separation between the two groups If n1 = 6, n2 = 8 and = 0.052 tail, Ucrit value is ____. 8 40 6 42 The Mann-Whitney U test is used with ____. an independent groups design a replicated measures design a correlated groups design none of the other three options Using SPSS, the appropriate steps to analyze data for student’s t test for correlated groups are _________ Compare Means > Paired Sample t test > Before_C > After_C Analyze > Compare Means > Paired Sample t test > After_C > Before_C Analyze > Compare Means > Paired Sample t test > Before_C > After_C Analyze > Compare Means > Before_C > After_C In SPSS, the results of analysing data for student’s t test are displayed ____. in a graph in a number of tables as a stem and leaf in a histogram In SPSS, the appropriate steps to analyze data for a one-way ANOVA are ____. you cannot perform ANOVA in SPSS One-Way ANOVA >Analyze > Compare Means Compare Means > One-Way ANOVA Analyze > Compare Means > One-Way ANOVA In SPSS, when you follow the steps to perform one-way ANOVA, ____. you will not be given the option to compute “descriptive statistics” you will be given the option to compute “descriptive statistics” you will be given the option to compute “descriptive statistics”, but you have to open a new file you will be given the option to compute “descriptive statistics”, but you have to restart SPSS