What additional information is sufficient to prove this (see picture)?

What is the greater volume 72 quarts or 23 gallons

Math question.. plz me .. best answer all

The line plot below represents the number of letters written to overseas pen pals by the students at the waverly middle school.each x represents 10 students. how many students wrote more than 6 and fewer than 20 letters. a.250 b.240 c.230 d.220