Chapter 7.2: Collection and Presentation of Data Mathematics Department Corpus Christi School

Suppose a new brand of whitening lotion is being introduced in the market. Whose testimony would you trust more: commercial models promoting the new product, or a friend who has actually tried the product and found it to be effective?

Classifications of Data Primary Data – data obtained directly from the objects being studied Secondary Data – data collected by another entity for a different purpose, and obtained through records or publications

Identify whether Primary or Secondary: Statistics from a PBA Basketball Game collected by the staff. Data from newspapers to be used in making an oral report. Census data obtained from the National Census and Statistics office to be used for another study.

Identify whether Primary or Secondary: 4. Data obtained from a survey undertaken by a researcher.

Primary sources of statistical data are the government institutions, business agencies and other organizations. Information derived from personal interviews can also be classified as primary data.

Secondary sources are books, encyclopedia, journals magazines, and research or studies conducted by other individuals.

Ways of collecting/gathering Data: Direct or Interview Indirect or Questionnaire Registration Method Experimental Method

Presentation of Data Textual – presented in paragraph form to allow description. Tabular – arranging data in rows and columns. Graphical – pictorial representation of data to highlight certain trends

Textual The total number of registered internet addresses reached 63 million after a record increase of 4.7million in the first quarter . More than 72 percent of the domain names were a part of a live website, up from 55percent at the height of the boom in December 2002 (The Philippine Star, June 11, 2004)

Tabular College Enrolment Business Administration 2365 Table 1. Students enrolled in XU SY 2011 - 2012 College Enrolment Business Administration 2365 Computer Studies 1854 Engineering 3164 Education 952 Liberal Arts 2715 Science 102

Graphical

If: Highlights of data are to be emphasized, then textual presentation is most appropriate. When dealing with large volumes of data that need to be summarized, the tabular presentation is very useful When trying to hold the reader’s attention, or when comparisons among data emphasized or made, graphical method is most appropriate

Classify either Primary or Secondary: Monthly income of 50 families surveyed in Quezon City. Effects of a drug being tested on mice in a laboratory setting. A survey of the leading causes of dropping out among high school students. Population figures for 60 barangays obtained from databases of the National Census and Statistics Office.

A summary report on the results of 2010 BAR Exam Results. Determine if the Data is presented better in Tabular, Graphical, or Textual The ranking and number of votes garnered by the winning senators in 2010 elections. A summary report on the results of 2010 BAR Exam Results. The ten highest paying jobs in the Philippines and their corresponding average annual salaries

A study to compare three brands of kitchen cleaners. Identify the type of data gathering method (direct, indirect, experimental, registration) A study to compare three brands of kitchen cleaners. A study to monitor the socio – economic status of residents in particular region. A study to identify the most trusted brands of vitamins by mothers. A study to determine the effectiveness of the fire drill being conducted by a government office

Quiz (1/4)

Identify what is being defined Data collected by another entity for a different purpose, and obtained through records or publication. Useful in dealing with quantitative data or with large amount of data. Pertains to data obtained directly from the objects being described.

Identify what is being defined 4. Data is presented in paragraph form to allow description about the data 5. A pictorial representation of data which is designed to highlight certain trends.

Classify either Primary or Secondary: Music preferences of 100 seniors in a public high school obtained through a survey. Statistics on the number of cases of meningococcemia for the first three quarters of 2013 quoted in a magazine.

Determine if the Data is presented better in Tabular, Graphical, or Textual 3. A summary report of the performance of Phil. Team in the 2012 SEA Games 4. Annual growth trend of Philippine Population during a ten-year period from 2000-10.

Identify the type data collection method best to be used in the ff.: 5. A study to monitor the performance of students with special needs. 6. A study to determine the breeding behaviour of a species of bird.

7. Which year level showed the least increase in average score from the pretest to the posttest?

Construct a Frequency Distribution Table from the following data: 25 22 32 19 12 16 77 18 34 49 89 80 60 35 52 7 37 68 23 61 71 15 55 84 41 30

Frequency Distribution Table Relative Frequency – quotient of the class frequency and the total number of scores Relative Percentage – relative frequency multiplied to 100 Class Mark – average the upper and lower limit of the class interval

Frequency Histogram A bar graph consisting of rectangles whose heights represent the frequencies of the classes.

Example 1 23 52 32 39 12 16 67 18 24 49 99 19 40 60 35 82 17 37 88 53 51 81 15 55 50 61 30

Example 1 R = H – L = 99 – 12 = 87 k = 𝑵 = 𝟑𝟎 = 5.47 ≈ 6 = 𝟑𝟎 = 5.47 ≈ 6 C = R/k = 87/6 = 14.5 ≈ 15

Example 1 Class Interval Freq. CM 87 – 101 2 94 72 – 86 79 57 – 71 3 64 42 – 56 6 49 27 – 41 34 12 – 26 11 19

Example 2 Major No. of Students Biology 8 Chemistry 2 Mathematics 4 Philosophy 13 Sociology 7 Engineering 15

Example 2