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22 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Statistics
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is the art and science of learning from data
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Statistics has three main
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Design
Description Inference |
Population and sample
Descriptive statistics Inferential statistics |
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Type of variables
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Qualitative or Categorical variables
Quantitative variables |
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Mean
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the average of the total SUM
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Median
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find the Median of {12, 3 and 5}
Answer: 5 |
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Quartiles
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Find the median, lower quartile and upper quartile of the following numbers.
12, 5, 22, 30, 7, 36, 14, 42, 15, 53, 25 (Put in ascending order) |
5, 7, 12 (Lower Quartile), 14, 15, 22 (Median), 25, 30, 36 (Upper Quartile), 42, 53
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Empirical Rule
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: for a bell-shaped distribution, about 68% (95%, 99.7%) of the data fall with in one (two, three) standard deviation of the mean.
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(SRS)
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simple random sample
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‘n’ subjects from a population is one in which each possible sample of that size has the same chance of being selected
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Convenience Sample
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a type of survey sample that is easy to obtain
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-Unlikely to be representative of the population
-Often severe biases result from such a sample |
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Volunteer Sample
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most common form of convenience sample
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-Subjects volunteer for the sample
-Volunteers do not tend to be representative of the entire population |
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Bias
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Tendency to systematically favor certain parts of the population over others
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Sampling Bias
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Occurs when using biased samples, which are based on sampling methods such as using nonrandom samples or having undercoverage
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Nonresponse bias
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occurs when some sampled subjects cannot be reached or refuse to participate or fail to answer some questions
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Response bias
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occurs when the subject gives an incorrect response or the question is misleading.
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Identify
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the population of all subjects of interest
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Construct
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a sampling frame which attempts to list all subjects in the population
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Use
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a random sampling design to select n subjects from the sampling frame
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Be
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cautious of sampling bias due to nonrandom samples
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Experimental units
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the subjects of an experiment; the entities that we measure in an experiment
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Treatment
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A specific experimental condition imposed on the subjects of the study; the treatments correspond to assigned values of the explanatory variable
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Explanatory variable
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Defines the groups to be compared with respect to values on the response variable
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The outcome measured on the subjects to reveal the effect of the treatment(s).
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The outcome measured on the subjects to reveal the effect of the treatment(s).
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