Find the area under the standard normal curve to the left of z=1.25.

For quite some time now, calculators have had statistical functions built in.  Here we need to use the stat. function normalcdf, which has only two inputs when we're working with z scores instead of raw scores.

Here,

normalcdf(-100,1.25) = 0.894

This same result could be obtained using a table of z-scores.