Let see that the snakes that are longer than 16.6 in are lomger than mean at 16.6-15=1.6 in
1.6:Sigma=1.6: 0.8=2 that means that all other snakes but longer than 16.6 in are inside +-2 Sigma. It is known that for normal distribution 95.4% of all snakes are inside +-2 Sigma
That means that 100%-95.4%=4.6% or about 5% of the snakes are longer than 16.6 in
