Question 927428
P(x &#8804; 290) =P(z < -.7746) = normalcdf(-100, -.7746)
normalcdf(-100, -.7746) Gives us the area Under the Normal Curve from (-100 < z < -.7746)
z-value -100 is used as a place holder, so to speak, as it is so.... far to the left ... that basically ALL the Area 
to the left of z-value -.7746 is then included. Use z-value -1000 if You wish.
................
.....Note how far z-value -3 is to the Left, for example
For the normal distribution: Below:  z = 0, z = ± 1, z= ±2 , z= ±3 are plotted.  
Area under the standard normal curve to the left of the particular z is P(z)
Note: z = 0 (x value: the mean) 50% of the area under the curve is to the left and 50%  to the right
{{{drawing(400,200,-5,5,-.5,1.5, graph(400,200,-5,5,-.5,1.5, exp(-x^2/2)), green(line(1,0,1,exp(-1^2/2)),line(-1,0,-1,exp(-1^2/2))),green(line(2,0,2,exp(-2^2/2)),line(-2,0,-2,exp(-2^2/2))),green(line(3,0,3,exp(-3^2/2)),line(-3,0,-3,exp(-3^2/2))),green(line( 0,0, 0,exp(0^2/2))),locate(4.8,-.01,z),locate(4.8,.2,z))}}}