Statistics and Probability Reviewer PDF

STATISTICS AND PROBABILITY REVIEWER | MIDTERM EXAM LESSON 1-2: INTRODUCTION TO STATISTICS AND PROBABILITY Philippine Statistics Authority ​ Central statistics authority of the Philippine government ​ Collects, compiles, analyzes, and publishes statistical information on economic, soci...

STATISTICS AND PROBABILITY REVIEWER | MIDTERM EXAM LESSON 1-2: INTRODUCTION TO STATISTICS AND PROBABILITY Philippine Statistics Authority ​ Central statistics authority of the Philippine government ​ Collects, compiles, analyzes, and publishes statistical information on economic, social, demographic, political affairs and general affairs of the people of the Philippines and enforces the civil registration functions in the country. Statistics ​ The science of collection, organization, presentation, analysis, and interpretation of data for decision making. C Collection O Organization P Presentation A Analysis I Interpretation Probability ​ Body of knowledge that focuses on activities that involve predicting chances and quantifying the randomness of events. WHY DO WE NEED TO STUDY THESE TWO? 1.​ Business – to monitor or estimate profits in business. 2.​ Economic – to analyze the relationship between supply and demand. 3.​ Government – to decide for local and national budgets. 4.​ Astronomy – predict weather conditions for emergency preparedness.  5.​ Medicine – they are used to test new drugs, and to work out the chance that patients develop side effects from drugs. 6.​ Politics – very much about strategy. 4 ESSENTIAL PROCESSES OF STATISTICS 1.​ Collection of Data – gathering of related information 2.​ Organization and Presentation of Data – systematic way of organizing data. It involves collecting, classification and arraying; and presenting data gathered in preparation for its analysis. 3.​ Analysis of Data – extracting relevant information from data at hand. It involves comparison and contrast; description; and statistical measurement to come up with numerical values and qualitative summary as a resulting conclusion. 4.​ Interpretation of Data – refers to the drawing of logical statements from the analyzed information. It involves generalizing; forecasting, and recommending solutions and interventions about the study. 2 BRANCHES OF STATISTICS DESCRIPTIVE STATISTICS ​ Group of statistical measurement that aims to provide the basic characteristics of a data set through tables and graphs and other descriptive measures such as measures of central tendency, measures of position and measure of variation. INFERENTIAL STATISTICS ​ Aims to infer or to make interpretations by making a concluding statement about the population based on the result derived from a data set. ​ Analysis of variance ​ T-Test ​ Chi-square test ​ Correlation and regression analysis LESSON 3: DATA AND CLASSIFICATION DATA – body of info or observations being considered by the researcher. When the DATA is processed, INFO is produced, which is the basis for decision making. CLASSIFICATION OF DATA Qualitative Data ​ Indicating a property, characteristics, feature. ​ It consists of NON numerical data that can be arranged into categories. Examples of this are gender, socio-economic status, civil status, color, and shape. Quantitative Data ​ Indicating amount, size, mass, etc. ​ It consists of numerical data, counts, and measurements. TYPES OF QUANTITATIVE DATA DISCRETE– a variable whose values are CONTINUOUS DATA – a variable that obtained through the process of counting. can be obtained through the process of measuring. LEVEL OF MEASUREMENTS OF DATA 1.​ Nominal ​ Data are qualitative ​ Have no order and thus only give names or labels to various category. 2.​ Ordinal ​ Can be quantitative or qualitative ​ Have order/rank. 3.​ Interval ​ Data is quantitative. ​ Can be ordered, and differences can be meaningfully calculated. ​ NO TRUE VALUE OF ZERO. 4.​ Ratio ​ Data is quantitative. ​ Have the highest level of measurement. ​ Starting point is ZERO. POPULATION ​ Collection of all outcomes, responses, measurements or counts that are of interest. PARAMETER– numerical value summarizing the data for an entire population. SAMPLE ​ Collection of all outcomes ​ refers to a subset of a population that is representative of the population from which it was selected. STATISTICS – numerical value summarizing the data for a sample. LESSON 4: DATA MANAGEMENT In collection of data, it is important that the researcher knows what data is needed, where and how to get the data. Data needed in a research may be collected using any of the following methods: METHODS OF COLLECTING DATA Interview Method ​ This is the method by which data is obtained through oral exchange of questions and answers by the researcher and the respondents. ​ This method is taxing and time-consuming, but it provides the flexibility of making follow-ups on the answers of the respondents. Questionnaire Method ​ It is a method where a set of questions is provided by the researcher, and the data is provided by the respondents by writing the responses to the items on the questionnaire. ​ Questionnaires may also be sent through emails or other form of technology for a wider coverage. Document Method ​ It is the method where a researcher avails of information gathered and stored by individuals or institutions, whether private, government, made available to other researchers. Observation Method ​ It is the method where data is acquired and recorded through direct observation by the researcher on an actual situation. It is relatively inexpensive. Experiment Method ​ It is a method where data is also gathered by the researcher himself just like an observation method. ​ The researcher is allowed to make manipulations​ as required by the experimentation process. ​ It is time consuming and expensive. In data collection, response rate is very important aspect. A low response rate may affect the validity of the conclusion to be made. Usually, the questionnaire method results in low response rate. WAYS OF PRESENTING DATA GATHERED Textual Form ​ It is where data is exposed through printed or spoken words, such as through printed or oral media. Graphical Form ​ It is where data is organized and presented through the use of various kinds of graphs. ​ It facilitates analyzing, summarizing and understanding voluminous set of data. ​ There are different types of graphs: line graph, bar graph, histogram, pie graph, cartograph, dot graph, stem-and-leaf, and box and whiskers. Tabular Form ​ Data is arrayed in rows and columns. TYPES OF GRAPHS ​ Line Graph ​ Bar Graph ​ Histogram ​ Pie Graph ​ Pictograph ​ Cartograph ​ Dot Graph ​ Stem-and-Leaf ​ Box and Whiskers