How do I find the area under the standard normal curve between z = .84 and z = 1.95.
I'll show you two ways, calculator and tables.
If you have a TI-83 or 84,
From the cleared main screen
Press 2ND
Press VARS
Press 2
you will see this on the screen --> normalcdf(
after that type .84,1.95)) so that you see this on the
screen ---> normalcdf(.84,1.95)
[If you can't find the comma key it is the key just to
the right of x2).
Press ENTER
You will see .1748661491, which you round to 4 places .1749
If you are not allowed to use a calculator,
Draw a normal curve on the z-axis (horizontal axis) marking
the middle point 0. Then mark off units right and left,
like this:
We want the area between the curve, the z-axis and the two
green lines.
So you look up 1.9 in the z column and go across the top to
the column that reads .05, and you will find either .4744 or
.9744, depending on which kind of normal table you have, the
kind that gives area from the center, or the kind that gives
area from the extreme left side.
Then you look up 0.8 in the z column and go across the top
to the column that reads .04, and you will find either .2995
or .7995, depending on which kind of normal table you have.
Then you subtract .4744-.2995 or .9744-.7995 and get .1749.
Edwin