Bryan's bakery kept track of their march and april sales of all of their bakery products and noticed there was a definite relationship between the two. based on the graph, if 50 lipsmacking butter biscuits were sold in the month of april, how many were sold in the month of march?

i don't understand the chart.

The best way I can explain the graph is: 

1. look at the line and mark a point where ever you see the line goes through a point (look at picture bellow)

2. best example on your graph is (40, 20): April 40...March 20

3. you will notice that march will always sell half the number of april's sale

another example in your graph: 
april sold 10....the line seem to be a 10, 5.....march sold 5

Why tho who need to use that much?