An 8th Grader is paid for the chores they do around the house. (Although they shouldn't be paid... They don't pay rent and eat for free. That is payment enough!)
The table shows the frequency and cumulative frequency of their undeserved income. Fill in the missing blanks.
Months Income Cumulative
1 to 3 $100 .............$-----
4 to 6 $------ ------$300
7 to 9 $ ------------ $400
10 to 12 $300 ............$-----