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Introduction to normal distribution - Normal Distribution and Z-Scores

Introduction to normal distribution

Lessons

Notes:
Properties of a Normal Distribution
\cdot About 68% of the population are within 1 standard deviation of the mean.
\cdot About 95% of the population are within 2 standard deviations of the mean.
\cdot About 99.7% of the population are within 3 standard deviations of the mean.

. properties of a normal distribution

Calculator Commands
\cdot To calculate the normal distribution probability between two data values:
normalcdf (lower bound, upper bound, mean, standard deviation)
- To calculate the area to the left of a data value, replace the lower bound by 1×1099-1 \times 10^{99}
- To calculate the area to the right of a data value, replace the upper bound by 1×10991 \times 10^{99}
\cdot To calculate a data value, given the area to the left of the data value:
invNorm (area, mean, standard deviation)
  • 3.
    Using “invNorm” to Solve Normal Distribution Problems
    The weight of chocolate bars produced by a factory is normally distributed with a mean of 225 grams and a standard deviation of 5 grams.
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Introduction to normal distribution

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