Define frequency density of a class interval.

In any grouped frequency distribution class intervals are of equal width.

Define frequency modulation.

What do you mean by class-frequency ? What is relative class-frequency of any class-interval?

In a frequency distribution having 6 class intervals the total frequency is 100 and cumulative frequency less than type and cumulative frequency more than type corresponding to the fourth class interval are 86 and 50 respectively. Find the frequency of the fourth class interval.

The marks of 30 students of a class of 10 in a test (out of 75) are given below 40, 21, 50, 37, 42, 37, 38, 42, 49, 52, 38, 53, 57, 47, 29, 59, 61, 33, 17, 17, 39, 44, 42, 39, 14, 7, 27, 19, 54, 51. Form a frequency table with equal class intervals.

Define: class-interval

Test scores out of 100 for a class of 19 students are as follows: 93, 84, 97, 98, 100, 78, 86, 100, 85, 92, 55, 91, 90, 75, 94, 93, 60, 81, 95 (a) Make a frequency table taking class interval as 91-100, 81-90, ... (b) Find the modal class (The "Modal class" is the class containing the greatest frequency). (c) find the interval that contains the median.

The difference between the upper and lower limits of a class interval is its width. (write True or false)