Selina Concise Class 7 Math Chapter 21 Data Handling Exercise 21B Solutions EXERCISE 21B (1) Sum of all observation = 53 + 61 + 60 + 67 + 64 = 305 Number of observation = 5 ∴ Required mean = 305/5 = 61 (2) First 6 natural number = 1, 2, 3, 4, 5, 6 […]