PMPs (project management professionals) often apply basic statistics to their projects. For the PMP certification exam, here's what you need to know when dealing with normal and cumulative distributions:

Equations are based on a normal distribution. In a normal distribution, keep the following in mind:

  • 68.3% of the data points fall within one standard deviation.

  • 95.5% of the data points fall within two standard deviations.

  • 99.7% of the data points fall within three standard deviations.

If you're looking at a normal curve and need a cumulative distribution, you should remember these values:

  • 0.15% of the data points fall between 0 and –3 from the mean.

  • 2.25% of the data points fall between 0 and –2 from the mean.

  • 16% of the data points fall between 0 and –1 from the mean.

  • 84% of the data points fall between 0 and +1 from the mean.

  • 97.75% of the data points fall between 0 and +2 from the mean

  • 99.85% of the data points fall between 0 and +3 from the mean.