The line plot below shows the lengths of strings mario used for an art project.

B. 36 feet.

Number of strings = 8

Step-by-step explanation:

From , the given line plot, the number of strings used by Mario = Number of cross on the line plot

i.e. Number of strings used by Mario =  8

Now by the given line plot , the sum of all the observations will be ( multiply all values by their corresponding frequencies or crosses and add ) :-

Now, the total length of ribbon used by Mario = Sum of all the observations

Hence, the total length of ribbon used by Mario 36 feet.