FREQUENCY DISTRIBUTION

Objectives; Organize data in the form of frequency distribution Distinguish an exact limits, class mark, class intervals, cumulative frequency, and cumulative percent

Frequency Distribution Is any arrangement of data that show the frequency of occurrence of values falling within arbitrarily defined ranged of variable known as CLASS INTERVAL NOTE: This is the case of a grouped frequency distribution

Ungrouped case: a frequency distribution is an ordering of data from either highest to lowest or lowest to highest with a frequency of occurrence

Class Interval – defined ranged of variable Class frequency – indicate the number of observations falling within the different class interval Exact limit – obtained by adding 0.5 to an upper limit or subtracting 0.5 from a lower limit Interval size – a number of scores included in a class interval - denoted by i Class mark – the mid-value of the interval - also known as the average of the lower limit and the upper limit Terms

Cumulative frequency – are obtained by adding successively, starting from the bottom, the individual frequencies Cumulative percentage – obtained by dividing each entry in the cumulative frequency by N or n and multiplying by 100 n – sample N – population - the total number of observation

CONSTRUCTING A FREQUENCY DISTRIBUTION STYPES: 1.Calculate the RANGE of the data by subtracting the lowest value from he highest value 2.Decide on the number of class interval 3. divide the range by the desired number of class interval 4.Choose an appropriate lower limit for the first class interval

6. Determine the rest of the CLASS INTERVALS using the procedure discussed 7. Count the number of observations or measurements falling within each class interval and enter the result in the frequency column

Assignment The data below are the grades of 50 students in Mathematics class a.Construct a frequency distribution with a class interval of 12. b.List down the exact limit, cumulative frequency, cumulative percent, & class mark