DATA FROM A SAMPLE OF 25 STUDENTS ABBAB0 00BABB BB0A0 A000AB ABA0BA

DATA ON HIGH TEMPERATURES IN O F Source: The World Almanac and Book of Facts

DATA ON TESTING CENTER THE NUMBER OF CARDIOGRAM PERFORMED EACH DAY FOR 20 DAYS

THE STAGES FOR STATISTICAL THINKING ARE: 1- DEFINE THE PROBLEM 2- DETERMINE WHAT DATA IS NEEDED 3- SELECT A SAMPLE 4- COLLECT DATA 5- SUMMARIZE AND ANALYZE DATA 6- MAKE INFERENCES AND DECISIONS BASED ON INFORMATION

The Journey to Making Decisions Begin Here: Identify the Problem DATA INFORMATION KNOWLEDGE DECISION MAKING Descriptive Statistics, Probability, Computers Experience, Theory, Literature Inferential Statistics, Computers

DATA: Specific observations of measured numbers. INFORMATION: Processed and summarized data yielding facts and ideas. KNOWLEDGE: Selected and organized information that provides understanding, recommendations, and the basis for decisions.

Descriptive Statistics include graphical and numerical procedures that summarize and process data and are used to transform data into information Descriptive Statistics include graphical and numerical procedures that summarize and process data and are used to transform data into information Inferential Statistics provide the bases for predictions, forecasts, and estimates that are to transform information to knowledge Descriptive Statistics include graphical and numerical procedures that summarize and process data and are used to transform data into information Descriptive Statistics include graphical and numerical procedures that summarize and process data and are used to transform data into information

USAUKARGENTINATURKEY Average3,32,72,83,9 Maximum4,54,411,98,9 Minimum0,80,2-10,9-7,5 Standard Error 1,21,06,75,8 Source: World Development Indicators (WDI) 2006 CD-ROM Comparison of the Growth Rates ( ) %

POPULATION: A complete set of individuals, objects or measurements having common observable characteristics. Examples of Populations - Names of all registered voters in TURKEY - Incomes of all families living in ANKARA - Annual return of all stocks traded on the ISTANBUL STOCK EXCHANGE - Grade Point Averages of all the students in your University - BILKENT

SAMPLE: A subset or part of a population Examples of Samples - Names of registered voters in TURKEY - Incomes of families living in ANKARA - Annual return of 150 stocks traded on the ISTANBUL STOCK EXCHANGE - Grade Point Averages of 500 students from different departments in your University - BILKENT

n: Sample N: POPULATION n: Sample

IR COMD POLS COMD IR Global COMD POLS IR Global Psychology IR COMD IR Psychology IR COMD IR COMD IR Psychology POLS IR POLS IR Psychology Global POLS COMD POLS IR POLS Global IR COMD POLS IR Global POLS Psychology DATA on the Departments From A SAMPLE OF 50 STUDENTS

The points scored during each game by a basketball team last season were: 60, 58, 65, 75, 50, 65, 60, 72, 64, 70, 58, 65, 56, 40, 68, and 55 Construct a dotplot of these data.

The following Table represents a sample of 50 final exam scores

YEAR - END AUDIT TIMES (in days) These data show the time in days required to complete year-end audit for a sample of 20 clients of a small accounting firm

Annual Incomes of 10 Families Income TL Family

MONTHLY STARTING SALARY (In TRL) GraduateMonthly Starting Salary 12,850 22,950 33,050 42,880 52,755 62,710 72,890 83,130 92, , , ,880 TOTAL: 35,280

Properties of the Mean 1- The Mean can be calculated for any set of NUMERICAL Data 2- The Mean is unique and unambiguous value. 3- The means of several sets of data can always be combined into the overall mean of all the data. 4- If each value in a sample were replaced by the mean, then ∑X would remain unchanged 5- The mean takes into account the value of each item in a set of data. 6- The mean is relatively reliable in the sense that means of many samples drawn from the same population generally do not fluctuate, or vary, as widely as other statistics used to estimate the mean of a population.

Properties of the Median In addition to the properties of the Mean; 1- It splits the data into two parts 2- The median is preferable to the mean because it is not so easily affected by extreme values.