Week 8 – HW

Week 8 – HW Question 1 Cross-sectional data are data: A. collected over time B. that are collected over a single period of time C. consisting of a single variable D. consisting of two or more variables Question 2 Ordinal data are: A. sorted into categories according to specified characteristics B. ordered or ranked according to some relationship to one another C. ordered, have a specified measure of a distance between observations but have no nature zero D. data which have a natural zero Question 3 The process of collection, organization, and description of data is commonly called: A. descriptive statistics B. statistical inference C. predictive statistics D. operational statistics Question 4 __________ is a measure of a linear relationship between two variables, X and Y. A. correlation B. range C. standard deviation D. median Question 5 The statistical measures that characterize dispersion are: A. Range, variance, standard deviation B. Mean, median, mode C. Range, mean, standard deviation D. Correlation, frequencies, standard deviation Question 6 Define standard deviation A. A measure of how dispersed observations around the mean B. The square root of variance C. The amount of variation error in the data D. A & B above Question 7 A discrete random variable is: A. outcomes over a continuous range of real numbers B. a numerical description of the outcome of an experiment C. one for which the number of possible outcomes can be counted D. one for which the number of possible outcomes cannot be counted Question 8 Define probability distributions. Describe two common probability distributions. 150 words Question 9 A confidence interval (CI) is a range of scores with specific boundaries that should contain the ______ mean. A. sample B. population C. standard error D. none of the above Question 10 The most common probabilistic sampling approach is: A. simple random sampling B. convenient sampling C. complex sampling D. error sampling Question 11 The hypothesis predicting that differences exist between the groups being compared is to the hypothesis predicting that no differences exist between the groups being compared as _____ hypothesis is to _____ hypothesis. A. null; alternative B. alternative; null C. one-tailed; two-tailed D. two-tailed; one tailed Question 12 Directional hypothesis is to non-directional hypothesis as _____ hypothesis is to _____ hypothesis. A. null; alternative B. alternative; null C. one-tailed; two-tailed D. two-tailed; one-tailed Question 13 A researcher was interested in the emotional effects of music on exam performance. Before their exam, a professor took one group of students into a room in which calming music was played. A different group of students were taken to another room in which new wave hard rock was being played. The students then took the exam and their scores were reported. What type of analysis would be most appropriate? A. Paired (dependent) t-test B. Independent (unpaired) t-test C. Analysis of Variance ANOVA D. Repeated Measures ANOVA Question 14 As the value of a t-test _____, the sample variance _____. A. increases; decreases B. decreases; increases C. increases; increases D. decreases; decreases Question 15 _____ is a procedure which allows us to predict an individual’s score on one variable based on knowing one or more other variables. A. Pearson product-moment correlation coefficient B. Coefficient of determination C. Regression analyses D. Point-biserial correlation coefficient Question 16 A fashion student was interested in factors that predicted the salaries of catwalk models. She collected data from 231 models. For each model she asked them their salary per day on days when they were working (salary), their age (age), how many years they had worked as a model (years), and then got a panel of experts from modeling agencies to rate the attractiveness of each model as a percentage with 100% being perfectly attractive (beauty). The most appropriate statistical analysis would be: A. T-test B. ANOVA C. Multiple-regression D. chi square Question 17 The _____ is the best fitting straight-line drawn through the center of a scatterplot that indicates the relationship between the variables. A. regression line B. negative relationship C. measure of variation D. multiple-baseline Question 18 Summarize statistical methods used in forecasting and the types of times series to which they are most appropriate. 150 words Question 19 List the principal rules for examining a control chart to determine if the process is in control. 150 words Question 20 Explain what a decision model is and list the three types of inputs common to decision models. 150 words Question 21 Explain the concept of risk analysis. 150 words Question 22 How do you compute return on investment? 150 words Question 23 List the three elements queuing systems have in common. Describe each element. 150 words Question 24 Explain optimization and optimal solution. 150 words Question 25 How can binary variables be used to model logistical conditions. Provide examples. 150 words