Posted: April 14th, 2015

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