a. 57
10. What are the class marks of the distribution having the classes below:
a. 28, 43, 58, 73, 88, 103
b. 34, 49, 64, 79, 94, 109
20 - 34
35 - 49
50 - 64
65 - 79
80 - 94
95- 109
c. 20, 35, 50, 65, 80, 95
d. 27, 42, 57, 72, 87, 102​