Page 205 - P1 Integrated Workbook STUDENT 2018
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Risk and uncertainty
3.2 Normal distribution
Some data is said to be ‘normally distributed’. This means it has:
a mean/average value
50% of values higher than the mean
50% of values lower than the mean
95% of values are within 2 standard deviations of the mean.
The number given in the normal distribution tables is known as the z score. The
z score allows us to calculate the proportion of the distribution meeting certain criteria
for any normal distribution.
Illustrations and further practice
Now try Example 2 from Chapter 14.
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