19. The following table shows the distribution of a group of families according to their expenditure per week. The median and the mode of the distribution are known to be 25.50 birr and 24.50 birr respectively. Two frequency values are however missing from the table. Expenditure (CI) 1-10 11-20 21-30 31-40 41-50 No of families (fi) 14 f2 27 f4 15 a) Find the missing frequencies. b) Find the mean
