L2 | NORMAL DISTRIBUTION

• NORMAL DISTRIBUTION

  • Symmetrical probability distribution representing a graph where the data clusters around the mean
  • Illustrated using bell shaped curve
• PROPERTIES OF A NORMAL DISTRIBUTION

  1. The curve is bell shaped
  2. The curve is symmetrical about its center
  3. The mean, mode, and median coincide at the center
  4. Tails are asymptotic to the baseline
  5. Width of the curve is determined by the standard deviation
  6. Area under the curve is 1 or 100%
• EMPIRICAL RULE

  • Three - sigma rule or 68% - 95% - 99.7%
• EMPIRICAL RULE

  • For a normal distribution, almost all observed data will fall within 3 standard deviations of the mean
• NORMAL DISTRIBUTION

  A) 68%

  B) 95%

  C) 99.7%

  D) 34%

  E) 13.5%

  F) 2.35%

  G) 50%

  
• PERCENTILE

  • Describes how a score compares to other scores in the set.