Given a frequency distribution table with marks and frequencies, find the median class, class size, modal class, and mean.

Frequency Distribution Table |c|c| Marks & f \\ 0-20 & 8 \\ 20-40 & 14 \\ 40-60 & 18 \\ 60-80 & 16 \\ 80-100 & 12 \\ Total & 68 \\ Step 1: Class size Class size = upper limit - lower limit of any class. Class size = 20 - 0 = 20. Class size = 20 Step 2: Median class Total frequency N = 68. Median position = (N+1)/(2) = (69)/(2) = 34.5. Cumulative frequencies: c|c Class & C.F. \\ 0-20 & 8 \\ 20-40 & 22 \\ 40-60 & 40 \\ 60-80 & 56 \\ 80-100 & 68 \\ C.F. first exceeds 34.5 at class 40-60. Median class = 40-60 Step 3: Modal class Modal class is the class with highest frequency. Highest f=18 for class 40-60. Modal class = 40-60 Step 4: Mean Midpoints x_i: 10, 30, 50, 70, 90. |c|c|c| Class & f & x_i & f x_i \\ 0-20 & 8 & 10 & 80 \\ 20-40 & 14 & 30 & 420 \\ 40-60 & 18 & 50 & 900 \\ 60-80 & 16 & 70 & 1120 \\ 80-100 & 12 & 90 & 1080 \\ & 68 & & 3600 \\ f x_i = 80 + 420 + 900 + 1120 + 1080 = 3600. Mean x = ( f x_i)/(N) = (3600)/(68). 3600 ÷ 68 = (3600 ÷ 4)/(68 ÷ 4) = (900)/(17). (900)/(17) = 52 (16)/(17). Mean = (900)/(17) (900)/(17)