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why is statistics important? |
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Definition
we encounter it everyday, we must understand so we don't make uninformed decisions and costly mistakes. Gives us the tools to differentiate between sound statistical conclusions and questionable ones drawn from bad data |
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Term
define the study of statistics |
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Definition
the methodology of extracting useful information from a data set |
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Term
what are the three essential steps for doing good statistics? |
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Definition
find the right data (which is complete and lacking any misrepresentation)
use appropriate statistical tools, depending on the data at hand
clearly communicate numerical information into written language |
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Term
generally, what are the two branches of the study of statistics? |
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Definition
descriptive statistics and inferential statistics |
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Term
define descriptive statistics |
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Definition
summarizing important aspects of data sets (charts, tables, typical values, variability.. i.e. batting average, divorce rates) |
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Term
what is the main growth in the field of statistics? |
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Definition
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what is inferential statistics? |
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Definition
drawing conclusions about a large data set |
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Term
what is a large data set called? |
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Definition
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Term
what is a population based on? |
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Definition
a sample set or set of sample data |
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Term
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Definition
all members of a specific group (not necessarily people) |
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Term
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Definition
a subset of that particular population |
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Term
what is a sample statistic |
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Definition
the results of the sample |
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Term
what is a population parameter? |
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Definition
usually an estimate of a total (like all of the population, which is hard to find since it is costly and impractical) the amount of the whole |
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Term
what are the two main reasons we are unable to use population data? |
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Definition
expensive, impossible to examine every member of a population |
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Term
sample data is usually collected in what two ways? |
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Definition
cross-sectional data and time series data |
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Term
define cross-sectional data |
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Definition
data collected by recording a characteristic of many subjects (like salary of graduates or price of gas in different states) could be at same point in time or approximately same time |
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Term
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Definition
recording a characteristic of a subject over several time periods (i.e. day week, month, year) like monthly sales of cars or daily price of stock for an entire quarter |
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Term
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Definition
general characteristic of a set of people, objects, or events where each observation varies in kind or degree |
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Term
define qualitative variable |
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Definition
label or name used to categorize the distinguishing characteristics (i.e. gender, race, profession, type of business) |
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define quantitative variable |
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Definition
has meaningful numerical values (i.e. height, temperature, age, weight) |
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Term
what two types of quantitative variables are there? |
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Definition
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Term
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Definition
value that can be counted like points in a basketball game (90) or a stock price 20.50 |
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Term
define continuous variable |
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Definition
uncountable values within a certain interval (i.e. weight between 100 and 101 so 101.12345 etc) however continuous variable may be counted in discreet terms like a weight of a baby (continuous) but we say 6 lbs 10 ounces |
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Term
what are the four major measurement scales? |
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Definition
nominal, ordinal, interval, and ratio scale |
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Term
what two measurement scales use qualitative variables? |
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Definition
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Term
what two measurements use quantitative variables? |
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Definition
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Term
what is the nominal scale? |
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Definition
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