An incomplete frequency disribution is given below: class intervals frequency 0-10 4 10-20 16 20-30 ---- 30-40 ---- 40-50 ---- 50-60 6 60-70 4 ................................. total................230 find the three missing frequencies of the table, given that median=33.5 , and mode = 34. Also calculate the mean using the empirical relationship between mean, median and mode.