Paper 4: Fundamentals of Business Mathematics & Statistic

4.8 I FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICS

Statistical Representation of Data

For the first class, width = 20.5 – 15.5 = 5

For the second class width = 25.5 – 20.5 = 5, so on.

(g) Frequency density : It is the ratio of the class frequency to the width of that

class-interval i.e. frequency density = width of the classclass frequency

For the first class frequency density = 51 =0.2

For the third class frequency density=^35 =0.6

(h) Percentage frequency : It is the ratio of class-frequency to total frequency expressed as percentage.

i.e. percentage frequency =width of the classclass frequency ́^100

In the table for the frequency 5, % frequency = 505 ́100 10= and so on.

4.2.3. Cumulative Frequency distribution:

As the name suggests, in this distribution, the frequencies are cumulated. This is prepared from a grouped

frequency distribution showing the class boundaries by adding each frequency to the total of the previous

one, or those following it. The former is termed as Cumulative frequency of less than type and the latter, the

cumulative frequency of greater than type.

Example 3 : The following is an array of 65 marks obtained by students in a certain examination : –

26 45 27 50 45

32 36 41 31 41

48 27 46 47 31

34 42 45 31 28

27 49 48 47 32

33 35 37 47 28

46 26 46 31 35

33 42 31 41 45

42 44 41 36 37

39 51 54 53 38

55 39 52 38 54

36 37 38 56 59

61 65 64 72 64