Post on 18-Jan-2016
The field of statistics deals with the collection, presentation, analysis, and use of data to make decisions and solve problems.
Statistical techniques can be used to describe and understand variability.
IME 301
Inferential statistics makes a decision about a particular population.
Descriptive statistics are methods for organizing and summarizing data.
Population refers to the collection of measurements on all elements of a universe about which we wish to draw conclusion or make decisions.
Sample is just a subset of observations selected from the population
IME 301
Data SummaryData Display and Graphical Methods: bar chart, pie chart, histogram
Measure of central tendencysample mean, sample median, population mean, mode
Measure of spread (variability)sample range, sample variance, sample standard deviation,population variance, quartile, inter-quartile
Data Display and Graphical Methods, cont.: box plot, frequency distribution, relative frequency histogram, time plot
IME 301
Mean Variance
Sample
Population
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ni
i i
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)(1
22
n
xxS
ni
i i
N
xNi
i i
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22
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Size
n
N
IME 301, Sept 98