Question 1175884
Normal approximation
mean is np or 120*0.61=73.2 turtles migrate and 46.8 do not migrate 
variance is np(1-p) or 73.2*0.39=28.548 turtles^2
sd is sqrt (V)=5.34 turtles 
probability is a z < (19.5-46.8)/5.34, using continuity correction factor
and z < -5.34, which is essentially 0.