To answer using the ti-83 04 ti-84,

-2nd VARS

-normalcdf

- enter numbers 170,220,200,50

-press enter

-.381168...

-change to a percentage

-38.12%

-hope this helps!

-2nd VARS

-normalcdf

- enter numbers 170,220,200,50

-press enter

-.381168...

-change to a percentage

-38.12%

-hope this helps!