Presentation of Data

Presentation of Data Prepared by: Ms. Bernabeth Jo T. Tendero

Textual Presentation • Presented in paragraph or in sentences • Includes : - enumeration of important characteristics - emphasizing the most significant features - highlighting the most striking attributes of the set of data (Basilia Ebora Blay)

Textual Presentation Disadvantage: • Readers sometimes get bored (Basilia Ebora Blay)

Tabular Presentation • Very effective and efficient means of organizing and summarizing data • A lot of information can be seen in one table • Makes comparison of figures quick under each category (Luis A. Tattao)

Parts of a Tables Table Heading Table Number Table 6. Fat Content of Diet by Age Bracket

Parts of the Table • Table heading – includes the table number and the title • Body – main part of the table containing the figures being presented

Parts of a Tables Table Heading Table Number Table 6. Fat Content of Diet by Age Bracket Stubs and Classes

Parts of the Table • Table heading – includes the table number and the title • Body – main part of the table containing the figures being presented • Stubs or classes – the categories describing the data, usually found at the left-hand side of the table

Parts of a Tables Table Heading Table Number Table 6. Fat Content of Diet by Age Bracket Stubs and Classes Caption

Parts of the Table • Table heading – includes the table number and the title • Body – main part of the table containing the figures being presented • Stubs or classes – the categories describing the data, usually found at the left-hand side of the table • Caption – designations of the information contained in columns, usually found at the top of the column. (Luis A. Tattao)

Frequency Distribution Table • A summary table in which data are arranged into conveniently established, numerically ordered class grouping or categories • A tabular presentation of data grouped into classes together with the number of observations in each class (Luis A. Tattao)

Steps in Constructing a Frequency Distribution Table • Determine the Range, R: Range = Highest Value – Lowest Value • Determine the approximate number of class intervals , k k = 1 + 3.3 log N N = population or the total number of observation • Obtain the class width , C

Steps in Constructing a Frequency Distribution Table 4. For Class Intervals (CI) Use the lowest score as the lower limit (LL) of the first interval , add (C-1) to it to obtain the upper limit (UL) of the first interval LL = LL of the previous interval + C UL = LL + (C-1)

Example Age of Patients in Hospital X, June 2004

Solution: • Determine the Range, R: R = 60 - 6 = 54 2. k = 1 + 3.3 log N = 1 + 3.3 log 36 = 6.1358 6

Solution • Obtain the class width , C = 9 • Class Intervals 6 is the LL of the 1st interval UL = 6 + (9-1) = 14 of the 1st interval

Solution 2nd interval LL = 6 + 9 = 15 UL = 15 + 8 = 23 Compute for the other intervals

Table 1. Ages of Patients in Hospital X, June 2004 N = 36

Assignment • Construct the frequency distribution table for the student’s scores in a statistics quiz

Answer to Assignment • Determine the Range, R: R = 9 – 2 = 7 2. k = 1 + 3.3 log N = 1 + 3.3 log 77 = 7.2254 7

Solution • Obtain the class width , C = 1 • Class Intervals Since there is only the class width is only 1 that means the frequency distribution table is ungrouped.

Table 1. Frequency Distribution of the students’ scores in a quiz in Statistics

Class Mark (x) • Midpoint of a class interval • Example: 60 – 68

Class Boundaries • A.k.a. exact limits • Obtained by subtracting 0.5 from the LL and adding 0.5 to UL • Example: 60 – 68 • 60 – 0.5 = 59.5 • 68 + 0.5 = 68.5 • Class Boundary: 59.5 – 68.5

Table 1. Ages of Patients in Hospital X, June 2004 N = 36 Calculate the class mark and the class boundaries of this FDT

Relative frequency (rf) • Percentage of frequency • Written in decimal form

Less than Cumulative frequency (<cf) • Obtained by cumulating frequency from top to bottom

More than cumulative frequency (>cf) • Obtained by cumulating the frequency from bottom to top

Practice Weights (in lbs.) of First Year High School Students in XYZ School

R = 120 – 35 = 35 k = 1 + 3.3 log 36 = 6.14 = 6 C = 35/6 = 5.8 = 6

Contingency Table • Has two or more frequencies shown • Use to record and analyzed the relationship between 2 or more variables

Example Table 3.5. The Contingency Table for the Opinion of Viewers on the New Program

Graphical Presentation • Data are presented in a form of graph or a diagram • A graph is a geometrical presentation of data • A graph must have a figure number and a title. If data came from another source, a source note should be incuded.

Advantages of a Graph • Helps to visualize certain properties and characteristics of the data at one glance (Tattao) • Helps facilitate comparison and interpretation without going through the numerical data (Blay)

Types of graph

Bar Graph • Comparing numbers by means of rectangles of uniform widths but of lengths proportional to the numbers being represented (Tattao) • Can be simple or compound • Can be vertical or horizontal • Used both for qualitative and quantitative data

Simple and Vertical

Horizontal and Compound

Line graph • Shows trends and increases and decreases in data sets • Obtained by plotting the frequency of the category above the point of the horizontal axis representing that category, and then joining the points with a straight line • Also used for both qualitative and quantitative data

From Table to Graph

Pie Chart • Useful when presenting the sizes of components that make up a certain whole entity • A circle subdivided into slices that represents various categories • Each slice is proportional to the percentages corresponding to that category

Presentation of Data