Complete the cumulative frequency table using the data in the tally table. Answer the questions below.
 

Rachel's class sold cupcakes to raise money for a field trip.  She made this tally table to show how many cupcakes were sold each hour.
1. How many cupcakes were sold in all by the end of the third hour?
2. How many more cupcakes were sold in the first three hours than in the last two hours?