Normal Distribution

1
Normal Distribution

• When large, random sets of data are collected and
  displayed in a histogram the histogram will be
  symmetrical and the frequency polygon appears as
  a bell shaped curve (if joined with curved lines)
  called a normal curve.
• A graph like that demonstrates the data has -
  normal distribution.

2

• normal distribution the type of distribution
  that usually results from a large, random set of
  data that has the following characteristics
• the majority of the data is in the middle
• the data is distributed symmetrically around the
  middle in the histogram
• the frequency polygon forms a bell shaped curve
  called the normal curve
• the averages are the same or close and near the
  middle of the set
• there are few, if any, outliers
• 68 of the data is within 1 standard deviation
• 95 of the data is within 2 standard deviations