MATH REVIEWER

• Statistics is a branch of Mathematics that deals with the collection,

  organization, presentation, analysis, and interpretation of data.
• Collection refers to the gathering of information or data.
• Organization or presentation involves summarizing data in graphical,

  tabular or textual forms.
• Analysis involves describing the data using statistical methods and

  procedures.
• Interpretation refers to the process of making conclusions based on the

  presented data.
• A population is a complete collection of all elements (scores, people...) to be

  studied.
• A census is a collection of data from every element in a population.
• A sample is a sub-collection of elements drawn from a population.
• In random sample, each member of the population has an equally likely

  chance of being selected. The members of the sample are chosen

  independently of each other.
• A convenience sample is a type of sample that is chosen so that it will be

  easy for the researcher.
• In a stratified random sample, the population is divided into subgroups, so

  that each population member is in only one subgroup. In this type of sample,

  individuals are chosen randomly from each subgroup.
• A cluster sample is a type of sample that consists of items in a group such

  as neighborhood or a household. The group may be chosen at random.
• A systematic random is obtained using an ordered list of population, thus

  selecting members systematically from the list.
• Data is a collection of facts or set of information or observation under study.
• Quantitative data consist of numbers representing counts or measurements,

  such as weights.
• Qualitative data can be separated into different categories that

  are distinguished by some nonnumeric characteristics.
• The nominal level of measurement is characterized by data that consist of

  names, labels, or categories only.
• The ordinal level of measurement involves data that may be arranged in

  some order but differences between data values either cannot be determined or are

  meaningless.
• The interval level of measurement is like the ordinal level. But meaningful

  amounts of differences between data can be determined. It has no inherent

  (natural) zero starting point (where none of the quality is present).
• The ratio level of measurement is the interval level modified to include the

  inherent zero starting point (where zero indicates that none of the quality is

  present).
• Quantitative data make use of numerical values while qualitative data

  involve categorical responses.
• Discrete data can assume finite number of values while continuous data can

  assume infinite number of values between any two real numbers.
• Measurements are classified into four categories namely nominal, ordinal

  interval and ratio.
• Data Gathering is defined as the procedure of collecting, measuring and

  analyzing accurate facts or information using standard validated techniques.
• Conducting Surveys

  In conducting Surveys, you may use interview method and the

  questionnaire method.
• Data is a collection of facts or information. They may be gathered by using

  the following methods.
• The person who gathers the data is called the investigator or the researcher
• Observing the Outcomes of Events

  Observing the outcomes of events is usually used by behavioral scientist

  who are primarily concerned with the behavior of either an individual or a group of individuals. The data are gathered either individually or collectively by means of observation.
• The person being observed is called the subject.
• Taking Measurements in experiments. This is done when you need to

  take the volume, temperature, distance , height and other quantities of

  objects in order to answer the needed data in an experiment.
• Reading Statistical Publications. This is advised when you need to

  consult records or history.
• A frequency table is a tally of the number of times a data value occurs. It shows clear and definite information about a set of data.
• The number of occurrences of a data value is called its frequency.
• Ungrouped data are data that are not organized, or if arranged, could only be from highest to lowest, or lowest to highest.
• Raw data. These are the data collected in a survey. We can hardly see any pattern in any set of raw data.
• Each item in the first column of the table is called class.
• The mode is the measure or value which occurs most frequently in a set of data. It is the value with the greatest frequency.
• The word modal is often used when referring to the mode of a data set. If a data set has only one value that occurs most often, the set is called unimodal.
• A data set that has two values that occur with the same greatest frequency is referred to as bimodal.
• When a set of data has more than two values that occur with the same greatest frequency, the set is called multimodal.