Descriptive or Summary Statistics
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Descriptive or Summary Statistics
In this section, you will expand your analysis by employing descriptive statistics or summary statistics to further describe characteristics of
the workforce. Your summary table described "how many" and also offered proportions in relation to the entire workforce, but through this
analysis, you can describe much more. For each of the following: salary, hourly rate, years of service, education, and age, calculate the:
mean, median, mode – average, middle, and most frequent data points in a set.
standard deviation – how spread out individual data points are from the mean; if data points vary greatly, the result is a higher standard
deviation and vice versa. It is referred to as a "measure of dispersion" calculated as the square root of the variance. (Note: standard
deviations – when calculating manually in Excel, you might see a slight difference between the result you get manually and the result you get
using the Analysis Toolpak, depending on whether your version of Excel requires you to use the function DSTDEV or STDEV.S).
variance – the average squared distance between the mean and each data value. It is also a measure of dispersion, which is used to
calculate the standard deviation. It is always nonnegative because the calculated squares are positive or zero. A small variance means that
the data points are very close to the mean and to each other; thus, a high variance tells us that the data points are very spread out from the
mean and from each other.
range – the difference between the highest (MAX) and lowest (MIN) values in a data set.
skewness and kurtosis – numerical measures to describe the shape of a data set and how close it is to a normal distribution. Skewness
describes how symmetrical the data is around the mean. Kurtosis describes height and sharpness of the central peak (its peakedness or
flatness) in comparison to a normal curve.
Resources
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Skewness and Kurtosis (https://lti.umuc.edu/contentadaptor/topics/byid/fe62277e-6e47-445e-b450-ab2dd309414b)
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Standard Deviation (https://lti.umuc.edu/contentadaptor/topics/byid/ab2b8e88-3b89-4e0b-808c-de905e37d283)
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Calculating Range (https://lti.umuc.edu/contentadaptor/topics/byid/60171f93-a4bd-4229-80bd-6bcce9745b33)
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Variance DVAR Function (https://lti.umuc.edu/contentadaptor/topics/byid/7b462317-dde3-488b-b881-dd8bd5ed9186)
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Descriptive Statistics in Excel (https://lti.umuc.edu/contentadaptor/topics/byid/dcb188dc-6625-4cde-821e-e775563f6673)
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Normal Distribution (https://lti.umuc.edu/contentadaptor/topics/byid/ed3d5529-0e0a-4d83-98ef-1676a7cb951f)
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Descriptive or Summary Statistics
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