Jar AWhat variation do you observe from the jar?

Jar AWhat variation do you observe from the jar?

What variations can you observe from the students in class?How would you relate these variations to statistics?

Overview of Statistics

Statisticsnot Stat-is-eeks!is a branch of science that deals with the collection, organization, presentation, analysis and interpretation of data

StatisticsInvolves data collection and presentation, and data analysisData collectionInvolves the means of gathering the dataData analysisInvolves the comparison of characteristics

Why do I need statistics in my degree / life?Statistics has many practical applications in real life.Business: Statistics is used to test consumer preferences. It can also determine the appeal of a certain product and, thus, its profitability.

Why do I need statistics in my course / life?Market Research: Statistics is the main tool for Market Research

Medicine: Statistics is used in medical research in order to find out which treatment/medicine is more effective for a certain disease

Applications or Uses of Statistics

To provide information

Applications or Uses of StatisticsTo provide comparison

Applications or Uses of StatisticsTo help discern relationships

Chart2

8537

8936

7647

7647

6862

6774

6079

beef consumption

chicken consumption

Year

Annual Pounds per Person

Beef and Chicken Consumption

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yearbeef consumptionchicken consumption

19708537

19758936

19807647

19857647

19906862

19956774

20006079

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00

00

00

00

00

00

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beef consumption

chicken consumption

Year

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Beef and Chicken Consumption

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Applications or Uses of StatisticsTo aid in decision-making / to justify a claim or assertion

Applications or Uses of StatisticsTo estimate unknown quantities

Applications or Uses of StatisticsTo predict future outcomes

Specifically, for businessesAccounting: Statistical methods are applied when conducting audits

Finance: Statistics are used to guide their investment recommendations. Statistics can also be used to determine the pattern of stocks.

Specifically, for businessesEconomics: Statistical methods are used to provide forecasts for the future economic state. For instance, it can forecast for inflation rates, unemployment rates, etc.

Areas of StatisticsDescriptive Statistics methods concerned with describing and summarizing sets of dataInferential Statistics methods that make possible the estimation of a characteristic of a population or the making of a decision concerning a population based on information provided by the sample

Exercise. Determine the area of statistics (descriptive or inferential) illustrated by the following:On a particular weekday, males own 30 of the 40 cars in the parking lot. Twenty of the parked cars are colored red, and 25 were Japanese-made.

Majority of the cars on the road are Japanese-made.Males own 75% of cars in the parking lot on this particular weekday.Red is the most preferred color of cars in the 21st century.

One can not go about without statistics.

Basic Statistical ConceptsPopulationthe totality of all individuals or entities from which information is desiredSamplethe subset of the population. Statistics use samples in order to estimate / describe the population

PopulationSampleBasic Statistical Concepts

Basic Statistical ConceptsPopulationthe totality of all individuals or entities from which information is desiredSamplethe subset of the population. Statistics use samples in order to estimate / describe the population

Basic Statistical ConceptsParameterNumerical value that describes a characteristic of the entire populationStatisticNumerical values that describes a characteristic of a sample

Basic Statistical ConceptsCensusProcess of collecting information from the entire populationSurveyProcess of collecting information from a sample

Usual uses of a censusTo determine the size of a countrys populationIdentify the characteristics of the people (i.e. age, gender, income level, etc.)Used to identify the current state of the economy (i.e. is it growing, stable, or declining)

Why not do a census all of the time?Most of the time, the population of interest is too large. Getting a census from a large population tends to be very expensive and very time consuming.In addition, results from a census can be out-of-date

Basic Statistical ConceptsPrimary dataType of data that is taken directly from the sourceCould be obtained by experimentation, observations, and surveysSecondary dataType of data that is taken from existing records such as those coming from external sources

Basic Statistical ConceptsExamples of secondary data:Data coming from:TVs, radio, InternetMagazines, newspaperReviews of studies about other topicsArticles done in the pastStoried told by reliable sources

What kind of data is accepted/used in statistics?Usually, primary data are the ones that are used in statistics since researchers are confident about the accuracy, reliability and integrity of the dataSecondary data can still be used. However, the procedure of the study should be checked.

Basic Statistical ConceptsVariablea characteristic or information of interest that is observable or measurable from every individual or object under consideration

Types of VariablesQualitative / Categoricalindicates a quality about the unit under study

Quantitative / Numericalindicates a quantity about the unit under study

Types of Quantitative VariablesDiscrete variableCan only assume countable numbers of distinct values (i.e. 0,1,2,)Continuous variablesCan assume infinitely many values corresponding to points on a line interval (i.e. height, weight)

Some ExamplesQualitative VariablesName/labelColor Rating (Good, Bad)Course CodeAge Group (young, old)Faculty RankQuantitative VariablesWeight of a newbornNumber of residents in a housing unitWeekly water consumptionTemperature

ILLUSTRATION: Social Weather Station (SWS) SurveysBackground:A total of 1200 adult Filipinos were interviewed.They were randomly selected from Luzon, Visayas and Mindanao.

13 February 2012Fourth Quarter 2011 Social Weather SurveyFINDINGS:Sixty-eight percent of adult Filipinos would not change their religion in the name of love, while 31% would.When it comes to love, 54% of Filipinos would follow their heart while 45% would follow their mind. Unwillingness to change their religion in the name of love is strongest among Muslims, with 56% who would definitely not change. Following one's heart rather than mind over matters of love is more prevalent among Filipinos in a relationship than those who are single. However, there are slightly more of the older 55 years old and above Filipinos who would follow their mind than heart.

Levels or Scales of Measurement

Nominalqualitative variable whose values are simply labels or names or categories without any implicit or explicit ordering of the labelsOrdinalqualitative variable whose values are labels or classes with an implied ordering in these labels

Levels or Scales of Measurement

Intervalquantitative variable with an arbitrary zero pointRatioquantitative variable with a fixed zero point

Some ExamplesNominal VariablesName/labelColor Course Code

Ordinal VariablesRating (Good, Bad)Age Group (young, old)Faculty Rank

Interval VariablesTemperature

Ratio VariablesWeight of a newbornNumber of residents in a housing unitWeekly water consumption

Exercise. Identify the level of measurement (nominal, ordinal, interval, ratio) of the following variables.Education level (none, primary, intermediate, , university)Weight (g)Height (cm)Age (yrs)Smoking status (smoker, non-smoker)Physical activity at home (mostly sitting, moderate, heavy)Number of units enrolled this termWeekly allowance Deans lister (yes,no)CGPA