IB Mathematics (SL)/Statistics and Probability

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Topic 6: Statistics and probability

Statistics

The normal distribution

A normal distribution is a continuous distribution defined by two parameters, mean $\mu$ and variance ${\sigma }^2$. Because of symmetrical shape of the normal curve, the mean is equal to the mode and median.

The standard normal distribution

Example of standard normal distribution curve

The standard normal distribution has mean of 0 and variance 1. The area under the curve (probability) is 1.

In order to find area under the normal curve, students can use normalcdf() in their TI calculator. The syntax is:

normalcdf (lower limit, uper limit, mean, standard deviation)