Figure 5.11: Vocabulary (raw scores) approximate
normal distribution
The variable vocabulary is approximately normally distributed. The values of skewness
and kurtosis are close to zero. (Most statistical packages adjust the values of skewness
and kurtosis to be zero in a normal distribution to aid interpretation—kurtosis actually
has a value of 3 when a distribution is normal), and the mean, median and mode are
almost identical (as they would be in a perfectly normal distribution).
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