The table below shows a frequency distribution of scores grouped into intervals for four different classes. Which class has the greatest mean score?
Intervals (0–10,3),(10–20,4),(20–30,5),(30–40,6)
Intervals (0–10,5),(10–20,5),(20–30,5),(30–40,5)
Intervals (0–10,6),(10–20,4),(20–30,4),(30–40,6)
Intervals (0–10,7),(10–20,3),(20–30,3),(30–40,7)
