The classes at the middle school want to raise money.

the sixth grade runs a bake sale for
5
5
hours and makes
$170
$170
.
the seventh grade sets up a dunking booth for
4
4
hours and makes
$112
$112
.
the eighth grade has a car wash and makes
$192
$192
in
6
6
hours.

which class has the highest rate for raising money?