Average hours of sleep (normal distribution)

How Little Sleep Can You Get Away With?

 

Nice example of a real life phenomena closely modelling a Gaussian normal distribution.  The average hours of sleep on a weeknight (for males) was 6.9 hours with a standard deviation of 1.5 hours.  Using this data, let’s calculate what percentage of men get a good night’s sleep.  The diagram indicates 27%.

Z = \frac{8 - 6.9}{1.5} = .73

 

normalCDF(.73,99) = .23 = 23\%