11./Sachin made the following runs in different matches: Runs 5415 15-25 25-35 35-45 45 65 Frequency 79 10 12 19 22 Calculate the average mean of the runs by Step-deviation Method (Ans. Average Mean = 33 875 runs 12. Calculate arithmetic mean of the following frequency distribution: Class less than 10 10-20 20-30 30-40 40-50 50-60 more than $60 Frequency 12 18 22 6