Mathematics

  Example 1:  Calculate the median for the following data: Marks 0 - 10 10 - 30 30 - 60 60 - 80 80 - 90 Number of students 6 20 37 10 7 Solution: We need to calculate the cumulative frequencies to find the median. Marks Number of students Cumulative frequency (cf) 0 - 20 6 0 + 6 6 20 - 40 20 6 + 20 26 40 - 60 37 26 + 37 63 60 - 80 10 63 + 10 73 80 - 100 7 73 + 7 80 N = sum of cf = 80, N/2 = 80/2 = 40 Since n is even, we will find the average of the n/2 th  and the (n/2 +1) th  observation i.e. the cumulative frequency greater than 40 is 63 and the class is 40 - 60. Hence, the median class is 40 - 60...

 

1. Natural Numbers are the counting numbers which starts from 1, 2, 3, 4, .... up to infinity.  2. Set of all Natural numbers contains all positive numbers starting from 1. 3. Standard notation for representation of Natural numbers is N. 4. Set of Natural numbers is the proper subset of Whole Numbers.