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?