Relative frequency distribution

Relative frequency distribution

1. Relative Frequency Distribution NADEEM UDDIN ASSOCIATE PROFESSOR OF STATISTICS https://www.slideshare.net/NadeemUddin17 https://nadeemstats.wordpress.com/listofbooks/

2. Relative Frequency Distribution:   A relative frequency distribution is made by dividing each frequency of a distribution by the total frequency and expressing the result either as a decimal or as a percent(Percentage frequency distribution).   1-The total of relative frequencies always equal to one . 2- The total of Percentage frequency distribution always equal to 100.

3. Example-1 The following data show the weights (in pounds) of 30 students of a school . Find relative frequency distribution. Find percentage frequency distribution . (c ) What percentage of the student‘s weight is less 117 pounds . (d ) What percentage of the student‘s weight is over 117 pounds . (e) What percentage of the student‘s weight is in between 100 and 126 pounds . Class Interval Frequency 91 - 99 3 100 – 108 7 109 – 117 11 118 – 126 7 127 – 135 2   30

4. Class Interval Frequency Relative Frequency Percentage Frequency 91 - 99 3 100 – 108 7 109 – 117 11 118 – 126 7 127 – 135 2   30 1 100 Class Interval Frequency 91 - 99 3 100 – 108 7 109 – 117 11 118 – 126 7 127 – 135 2   30 1 100 Solution : (a) And (b)

5. (c) From column four Percentage of the student's weight is less 117 pounds = 10% + 23.33% + 36.67% Percentage of the student's weight is less 117 pounds = 70 %   (d) From column four Percentage of the student's weight is over 117 pounds = 23.33% + 6.67% Percentage of the student's weight is over 117 pounds = 30%

6. (e) From column four Percentage of the student's weight is in between 100 and 126 pounds = 23.33% + 36.67 % + 23.33 % Percentage of the student's weight is in between 100 and 126 pounds = 83.33%

7. We can also classify information according to qualitative characteristics, such as blood group, color of cars , race, religion and gender, which do not fall into numerical categories. Example – 2 The following data show the birthdays of 25 children. Days f Mon Tue Wed Thu Fri Sat Sun 4 2 5 2 2 7 3 25

8. Find relative frequency distribution and percentage frequency distribution . (b) Estimate the number of birth on Saturday if the total birth is 10,000 in a city . Solution : (a) Days F Relative frequency Percentage frequency Mon Tue Wed Thu Fri Sat Sun 4 2 5 2 2 7 3 0.16 0.08 0.2 0.08 0.08 0.28 0.12 16 8 20 8 8 28 12   25 1 100 (b) Number of birth on Saturday = 10,000 × 28% = 1200 births