Lesson 1: Basics of Statistics PDF

Gerome H. Bautista First Semester 2024-2025 It is the science of collecting, organizing, analyzing and interpreting data in order to make sound decisions. It is usually associated with numerical computations where statistical data were expressed in figures (e.g. monthly sales, cost and profit,...

Gerome H. Bautista First Semester 2024-2025 It is the science of collecting, organizing, analyzing and interpreting data in order to make sound decisions. It is usually associated with numerical computations where statistical data were expressed in figures (e.g. monthly sales, cost and profit, population). 1. COLLECTION OF DATA is the process of collecting measurements and frequencies of occurrence. 2. ORGANIZATION OF DATA involves the classification and presentation of obtained data in tables or graphs. 3. ANALYSIS OF DATA utilizes numerical computations from which quantitative and qualitative descriptions are formulated. 4. INTERPRETATION OF DATA includes the making of conclusion which will lead you to formulate inferences as well as predictions. DESCRIPTIVE STATISTICS is concerned with the techniques that are used to describe or characterize the obtained data. INFERENTIAL STATISTICS involves techniques that use the obtained sample data to infer, predict or generalize. DATA refers to facts or figures measured or collected on some characteristics of a population or sample. POPULATION consists of all the members of a group of items or individuals. SAMPLE is a subgroup or subset of the population. PARAMETER is a numerical measure that describes or quantifies a characteristics of a population. STATISTIC is a numerical measure that describes or quantifies a characteristics of a sample. A variable is a numerical characteristic or attribute associated with the population or sample being studied. Variables refer to aspects of differences among the elements in the population or sample. A constant is a variable in a statistical study that can assume only one value or characteristic.  categorical; names; labels Qualitative counting Variables Discrete Quantitative numbers Continuous measuring 1. Monthly allowance of college students 2. Socio-economic status of families in your barangay 3. IQ scores of SMU students 4. Contestants in a Statistics quiz 5. Number of days in the month of July 6. Percentage of students who are dropped outs of our school 7. Length of a residential lot 8. People at the park at 6 pm 9. Distance traveled by bus for one day 10.Mango yield per tree 11.Volume of a pail of water 12.Number of aces in a deck of cards 13.Floor area 14.Number of millimeters of rainfall in a city during various months of the year 15.Velocity of a car in kilometers per hour  What does the number in your basketball jersey mean? Does your ID number mean something? It is simply the systematic process of assigning number to “something” (Nunnally, 1978). This number assigned represents a qantified attribute of the variable. Measurements are classified into four scales. In selecting the statistical tool to be used for drawing inferences, the scale of the data gathered must be of utmost consideration. 1. IDENTITY refers to the meaning each number has. 2. MAGNITUDE refers to the property of “moreness” of “something” in the number. 3. EQUAL INTERVALS refers to the difference between any two consecutive numbers referring to the same amount of difference in the attribute. 4. ABSOLUTE/TRUE ZERO refers to the presence and absence of “something” in the zero point of the measurement.  It is the lowest level of measurement. It is used as a measure of identity, name, or classification. The numerical assignments to each identity or classification indicate that the elements are different, but the difference is not according to order or magnitude. It is also called the “categorical level.”  It refers to measurements that reflect rank or order of the individuals or objects. Numbers employed in ordinal scale when we rank categories with their respective numberings indicate only position in an ordered series, but this does not show how much of a difference exists between successive positions in the scale.  It possess the properties of magnitude and equal interval but not “absolute zero”. It establishes a uniform unit in the scale so that any distance between two consecutive scores is of equal magnitude. Zero (0) in this scale does not mean “absence” of the item or object being measured.  It is the highest level of measurement. It has all the properties of interval scale and in addition, has an absolute zero point. Because of the zero point, it is legitimate to compute ratios with the scale readings by which meaningful comparisons can be made.  SOCIOECONOMIC NAME AGE HEIGHT RELIGION STATUS ADA 17 5.4 Islam Average BERNA 18 5.6 Catholic Low CARLOS 18 6.0 Born Again Low JOSE 20 6.1 Orthodox High LARI 16 5.9 Catholic High 1. The average life expectancy in New Zealand is 78.49 years. 2. A diet high in fruits and vegetables will lower blood pressure. 3. The total amount of estimated losses for Hurricane Katrina was $125 billion. 4. Researchers stated that the shape of a person’s ears is relative to the person’s aggression. 5. In 2013, the number of high school graduates will be 3.2 million students. 1. Weight in pounds of newborn babies 2. Speed of a car 3. Length of milkfish in a fishpond 4. Eye color 5. Skin tone 6. IQ level of Grade 1 pupils as low, average, and high 7. Educational attainment 8. Temperatures of hair dryers 9. Monthly salary of employees of RTP Company 10. Religious affiliation