Question 525398
<pre>
{{{drawing(400,200,-5,5,-.5,1.5, graph(400,200,-5,5,-.5,1.5, exp(-x^2/2)), 
 
green(line(1.22,0,1.22,exp(-1.22^2/2)),line(2.15,0,2.15,exp(-2.15^2/2)),
line(1.22,0,1.22,exp(-1.22^2/2)),
line(1.27,0,1.27,exp(-1.27^2/2)),
line(1.32,0,1.32,exp(-1.32^2/2)),
line(1.37,0,1.37,exp(-1.37^2/2)),
line(1.42,0,1.42,exp(-1.42^2/2)),
line(1.47,0,1.47,exp(-1.47^2/2)),
line(1.52,0,1.52,exp(-1.52^2/2)),
line(1.57,0,1.57,exp(-1.57^2/2)),
line(1.62,0,1.62,exp(-1.62^2/2)),
line(1.67,0,1.67,exp(-1.67^2/2)),
line(1.72,0,1.72,exp(-1.72^2/2)),
line(1.77,0,1.77,exp(-1.77^2/2)),
line(1.82,0,1.82,exp(-1.82^2/2)),
line(1.87,0,1.87,exp(-1.87^2/2)),
line(1.92,0,1.92,exp(-1.92^2/2)),
line(1.97,0,1.97,exp(-1.97^2/2)),
line(2.02,0,2.02,exp(-2.02^2/2)),
line(2.07,0,2.07,exp(-2.07^2/2)),
line(2.12,0,2.12,exp(-2.12^2/2))),


locate(4.8,-.01,z),locate(4.8,.2,z)
  
)}}}


You want to know what decimal fraction the green area
is of the whole area on the normal curve.

Notice it starts at z=1.22 on the z-axis and goes to z=2.15.

On a TI-83 or 84 calculator you can find it by

normalcdf(1.22,2.15).  You get .0954549502

On a normal table you look up 

z = 2.15 and find either .4842 or .9842, depending on what
kind of z-table you have.

Then you look up 

z = 1.22 and find either .3888 or .8888, depending on what
kind of z-table you have.

Then you subtract the two values

.4842-.3888 or .9842-.8888

and you'll get .0954

That's the fraction of the total area which the green
area is of the entire area.  As a percent the green area
is 9.54% of the total area between the z-axis and the normal
curve.

Edwin</pre>

Edwin</pre>