statistics

• Statistics is the science of collection, organizing, presenting, analyzing, and interpreting data to assist in making more effective decisions.
• Data is everywhere and statistical techniques are used to make many decisions that affect our lives.
• Prices of books (P0.00 does represent no cost, and a P300.00 book does cost twice as much as a P150.00 book.)
• No matter what your career, you will make professional decisions that involve data.
• An understanding of statistical methods will help you make these decisions effectively.
• Inferential statistics are concerned with generalizing about a population or other groups of data based on the study of the sample.
• Descriptive statistics deal with the methods of organizing, summarizing, and presenting a mass of data to yield meaningful information.
• Population consists of the totality of the observations with which we are concerned.
• Statistic is any numerical values describing a characteristic of a sample and usually represented by the ordinary letters of the English alphabets.
• Sample refers to a finite number of objects selected from the population.
• Distances (in km) travelled by cars (0 km represents no distance travelled, and 400 km is twice as far as 200 km.)
• The number of respondents or subjects to form a sample is termed as the sample size.
• Polynomic data takes the form of a word with more than two options, such as education - primary school, secondary school and university.
• Primary data refers to the information which is gathered directly from an original source or which are based on direct or first-hand experience using methods like surveys, interviews, or experiments.
• Discrete data is the result of counting and is expressed as whole numbers.
• Interval Scale is the scale on which zero is arbitrary and does not reflect the absence of an attribute.
• Ratio Scale possesses all of the characteristics of interval scales but has a true zero point and a case where 0 is on a scale indicates the total absence of the property being measured.
• Nominal Scale involves categorizing cases according to the presence or absence of some attribute and is generally used for the purpose of classification.
• Dichotomic data takes the form of a word with two options, such as gender - male or female.
• Ordinal Scale is the simplest scale which orders people, objects, or events along some continuum and offers at least a rough indication of quantitative differences; they can also be categorized and ranked; numbers are used only to place objects in order.
• Secondary data refers to the information taken from published/unpublished materials that have been previously gathered by other individuals, researchers or agencies.
• Quantitative (Numerical) Data are always numbers and are the result of counting or measuring attributes of a population.
• Continuous data is the result of measuring and is not necessarily whole numbers.
• Cochran (1977) presented a set of formulas that can be used to determine the sample size.
• The level of significance, 𝛼, can take any of the standard values namely, 0.01, 0.05, and 0.10.