Population: All dog owners in Whatcom CountySample: dog owners who came in to Petsmart on the day of the surveyParameter: number or proportion of dog owners in whatcom county who would use each locationStatistic: number or propotion of dog owners who come in to Petsmart on the day of the survey who would use each locationVariable: X = prefered location of a dog ownerData: the specific values of X
QUANTD 2. QUAL 3. QUAL 4. QUANTC QUANTD 6. QUANTC 7. QUAL 8. QUALQUAL 10. QUANTC 11. QUANTD 12. QUAL
Chapter 1S A M P L I N G A N D D A TA
ProbabilityP r o b ab i l i t y i s t h e m a t h e m a t i c a l t o o l u s e d t o s t u d yrandomness.
StatisticsStatistics is the science ofc o l l e c t i n g, o r g a n i z i n g, s u m m a r i z i n g, a n d a n a l y z i n gd a t a t o d r aw c o n c l u s i o n s o r a n swe r q u e s t i o n s .I n a d d i t i o n , s t a t i s t i c s i s ab o u t p r ov i d i n g a m e a s u r eo f c o n f i d e n c e i n a ny c o n c l u s i o n s .
1.2 Statistics Descriptive Statistics consist of organizing and summarizing data through numerical summaries, tables, and graphs. Inferential Statistics uses methods for drawing conclusions and determining how reliable they may be.
Do not look in your bag!GROUP WORK 1. Break into pairs. 2. One person should select four pieces of twine (one at a time, returning each piece before selecting the next). The other person should record the length of each piece and then calculate the average of the lengths. You should then switch jobs and repeat the process.
1.4 Key Terms The entire group to be studied is called the popultion. For large populations a subset of the population called a sample is selected and studied. A statistics is a numerical summary of a sample. A parameter is a numerical summary of a population. A statistic can give us an estimate of a parameter or allow us to test the validity of an established parameter.
1.4 Key Terms Goal: A representative sample, one in which the relevant characteristics of the sample match those of the population. A study suffers from bias if its design or conduct tends to favor certain results.
1.4 Key Terms A variable, often represented by X or Y is a characteristic of interest of the individuals in the sample. Data are the actual values of the variable, often represented by x or y.
The Whatcom County Parks Department isEXAMPLE considering two possible locations for a new leash free area where people can bring theirIdentify each of thefollowing: dogs. To find out which location would be more popular, a survey is taken throughoutPopulation one day at Petsmart in which dog owners areSample asked which they would be more likely use.ParameterStatisticVariableData
1.5 DataMost variables can be classified as either qualitative orquantitative Qualitative variables allow for classification of individuals based on some attribute or characteristic. Quantitative variables provide numerical measures of individuals. Arithmetic operations can be performed on the values of quantitative variables and will provide meaningful results.
1.5 DataWe can further classify quantitative data as discrete orcontinuous. A discrete variable is the result of counting. A continuous variable is the result of measurement.
1. The number of pairs of shoes you ownGROUP WORK 2. The type of car you drive.Determine the 3. Where you go on vacation.correct data type: 4. The distance from your home to the nearest grocery store.Qualitative 5. The number of classes you take per schoolQuantitative year.(discrete) 6. The tuition for your classes.Quantitative 7. The type of calculator you use.(continuous) 8. Movie ratings. 9. Political party preferences. 10. Weight of sumo wrestlers. 11. Number of correct answers on a quiz. 12. People’s attitude towards the government