If 1−5,6−10,11−15,... are the classes of a frequency distribution then the size of the class is _____
If the class-marks of a frequency distribution are 10.5, 16.5, 22.5, 28.5, 34.5, then the class-size is
In a grouped frequency distributions, the class intervals are 1-10, 11-20, 21-30,....The class width is
If the class Mark in a frequency distribution are 19.5,26.5,33.5,40.5,47.5,54.5,61.5, then the class size of distribution is