A tabular arrangement of data thatshows the frequency of occurrenceof the different values of thevariables.
It is use to rank the disorganized data from highest to lowest or vice versa. It is use to organize tabulation of the no. of the individual scores located in each category X for score and f for the frequency. It is use to summarizes the distribution of the values.
Class interval - the range of such class of data is called the Class Interval. Class limit - The lower and upper limits of a class interval are known as Class Limits. Class boundaries – the values between the upper limit of one interval and the lower limit of the next interval. Class mark - Midpoint of a class interval. Class frequency - Refers to the number of observation belonging to a class interval. Class size - the total number of observations on which class interval is formed.
Problem A: Using following data, construct a frequency distribution table of weight of 50 boys. Use 8 class intervals of equal size and also find class boundaries and mid class. 125, 108, 119, 115, 129, 140, 137, 130, 129, 124, 111, 100, 127, 130, 150, 96, 141, 122, 122, 136, 92, 124, 139, 109, 105, 114, 131, 124, 136, 132, 151, 127, 125, 123, 119, 124, 134, 129, 104, 102, 125, 148, 143, 124, 123, 101, 147, 100, 126, 131.
Range = Largest Observation - Smallest ObservationHere, Largest Observation = 151 Smallest Observation = 92 Range = 151 - 92 = 59
From the problem we use 8 class intervals of equal size and the range for the given data is 59, so in order to find the size of class interval.The formula will be; Size of class interval = Range Total no. of class intervals Size of class interval = 59/8 = 7.375 = 8 (note: in case the fraction appears, the next higher whole number is usually taken as the size of the class interval).
Weigh t Tally frequency 92-98 II 299-106 IIIII I 6107-114 IIII 4115-122 IIIII 5123-130 IIIII IIIII IIIII III 18131-138 IIIII II 7139-146 IIII 4147-154 IIII 4
Prepared by : Ms. Ma. Teresa B. BerondoProf.: Maria Fe GuetaInferential Statistic