Quantitative Research Techniques + Statistics – Peregrine Exam Questions and Answers Graded A+

Quantitative Research Techniques + Statistics – Peregrine Exam
Questions and Answers Graded A+


1. A company developed a smartphone whose average lifetime is unknown. In order to esti
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mate the average, 200 smartphones are randomly selected from a large production line an
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d tested; their average is found to be 5 years. The 200 smartphones represent:: a sample
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2. Significance level: Measures the reliability of a statistical inference
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3. inferential statistics: Process of using sample statistics (mathematics) to draw conclusio
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ns about population parameters
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4. mutually exclusive: Events that cannot occur at the same time.
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5. sampling error: the difference between the results of random samples taken at the same t
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ime
6. non-
sampling error: occurs when the sample data are incorrectly collected, recorded, or analyze
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d. Three types of errors: data acquisition errors, non-response errors (or bias), selection bias
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7. Design of a good survey components: short survey, short/simple questions, start with d
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emographic questions, ues dichtomous (yes-no) and multiple choice
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8. Direct observation: example: counts backpacks on campus for a day
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9. stratified random sample: a sample from selected subgroups of the target population
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in which everyone in those subgroups has an equal chance of being included in the resear
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ch

example: The manager of a customer service division wants to know if the customers in the past 1
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2 months are satisfied with their purchase of CD's. There are four types of CD's.
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10. Joint Probability: the probability of the intersection of two events
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11. Union of two events: The union of events A and B is the event containing all sample poin
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ts that are in A or B or both
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12. Marginal Probability: the probability of a single event without consideration of any other
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event
13. Conditional Probability: the likelihood that a target behavior will occur in a given circ
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, umstance
14. Bayes Law: calculates posterior probability
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15. exhaustive: including everything possible; very thorough or complete
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16. Central Limit Theorem (CLT): The name of the theorem stating that the sam-
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pling distribution of a statistic (e.g. x ) is approximately normal whenever the sample is large an
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d random. Allows us to draw conclusions about the population based on strictly sample data.
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17. sampling distribution of the mean: 1. the sampling distribution of the mean has a differ
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ent mean from the original population
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2. the standard deviation of the sampling distribution of the mean is referred to as
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