1. Frequency Distributions The arrangement and display of data in the form where the observed value is paired with its frequency Example Tabulate the number of rooms in the houses occupied by 25 families from the data 1 2 4 3 4 2 5 3 2 2 4 1 2 3 5 1 3 5 1 3 3 1 3 1 1

2. Note down the values from the lowest to the highest Put in one column In the other column the number of times each value has occurred is noted with the help of bars Frequency is found out

3. Number of rooms TalliesFrequency 1234512345 IIII II IIII IIII II III 7573375733 25 Out of 25 families 7 were living in 1 room each,5 in 2 rooms, 7 in 3 rooms etc.

4. Relative Frequency The concerned frequency is divided by the number of observations or the total frequencies Relative frequency =

5. Frequency Distribution for Number of heads obtained by 30 students Observation s (x) Frequency (y) Relative frequency (f/N) Percentage Frequency (f/N) x 100 022/307 155/3017 288/3027 399/3030 444/3012 522/307 Sum30100

6. Class Limits Lowest and the highest values of a class Class Interval Difference between the upper limit and the lower limit of a class Class Frequency Number of observations belonging to a particular class Class mid point

7. Cumulative Frequency Distribution Marks obtainedNumber of students Marks obtainedCumulative Frequency 10 Not more than 1010 2030Not more than 2040 3035Not more than 3075 4028Not more than 40103 5039Not more than 50142 6020Not more than 60162 7010Not more than 70172 We can use the instead of

8. Question- The following data pertain to weights of 33 students of a class 42 74 40 60 82 115 41 61 75 83 63 53 110 76 84 50 67 65 78 77 56 95 68 69 104 80 79 79 54 73 59 81 100 Prepare a suitable frequency table Solution Highest value is 115 Lowest value is 40 Range of the data is 75(115-40)

9. Class IntervalsTally MarksFrequencies 40 to under 50III3 50 to under 60IIII5 60 to under 70IIII II7 70 to under 80IIII III8 80 to under 90IIII5 90 to under 100I1 100 to under 110II2 110 to under 120II2 Total33 Advantage of Frequency distribution table  Highlights some important characteristics of the data –range  Selection of class boundaries is subjective-different width We can use “40 but less than 50”,”40 and under 50” instead of “40 to under 50”

10. Problem for you Prepare a statistical table from the following weekly wages of 40 workers of a factory 8823272886949386 2967569993488032 9639265487568483 2439494676964667 2678504443467999