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STANDARD DEVIATION
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online sources for further exploration
Baseball

Biomedical electronics

Bioretention applications

Election polls

Estimating trees

Food technology

Gallup polls

Indiana custom rates

Mining

Petroleum technology

Six sigma 


Standard deviation in spreadsheets

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STEP FUNCTIONS
A step function is a mathematical relationship that has a graph that looks like
steps. As a result, the function has the same output for multiple input values. For
example, a telephone company may charge you 12 cents a minute for a long-dis-
tance call. A 3.3 minute, 3.7 minute, or 4.0 minute call will be charged 48 cents,
or the price of a four-minute phone call, because the phone rate rounds up for
every fraction of a minute beyond a whole value. In this case, the price of the
phone call in dollars, 
p, can be determined by the function p = 0.12
⌈t⌉, where t
is the length of the phone call in minutes. The 
⌈t⌉ indicates that the value for t
should be rounded up to the nearest integer. This type of step function is called a
ceiling function and is sometimes represented by the expression 
ceil(t). There-