So, basically there is 5 minutes and the number of times occuring is 5 so its 5x1 which is 5 and then there is 10 minutes and the number of times occuring is twice so its 2x10 which is 20. Next, is 15 minutes and the times occuring is 2 so, 2x15 which is 30. And finally theres 20 minutes and the amount of times occuring is once so 20x1 which is 20. Then you add them all up which is 5+20+30+20=75. And the formula for mean/average is The sum of all number/ The amount of numbers there are so 75/6 is 12.5.
