Unformatted text preview: MATH1342
1S1 – 8:00-10:10
1S2 – 10:15-12:15
3S7 – 6:00-8:00
2S3 – 1:00 – 3:00
2S4 – 3:10 – 5:10 Daryl Rupp What proportion of southern Iowa homes
have soft water? A sample of 6 homes in 6
cities found 3 had soft water. What is the
conclusion? 1. 0.50 of the homes in southern Iowa have soft water.
2. Approximately 0.50 of the homes in southern Iowa have soft water.
3. We can not make a conclusion.
4. Between 0.33 an 0.67 of the homes have soft water,
5. There is an 80% confidence that between 0.33 and 0.67 of the homes have soft water. STATISTICS
STATISTICS The science of collecting, organizing, summarizing and analyzing data to draw conclusions or answering questions, with a given amount of confidence concerning the answer.
In other words, it is the method or process used in finding an answer to a question, with a specific amount of confidence that the answer is correct. TWO TYPES OF STATSISTICS
TWO Descriptive is about organizing and summarizing data in order to picture the nature of the population or sample represented by the data. (2 – 3)
Inferential is the process or method of extending the answer for a sample to the entire population and measuring the reliability of that answer (9 – 11, 4) DEFINITIONS
DEFINITIONS POPULATION: The entire group of individuals being investigated (size is N). Must be precisely defined.
INDIVIDUAL: One member of the entire group or population.
SAMPLE: A subset of a given size (n) taken from the population. DEFINITIONS
DEFINITIONS VARIABLE: A given aspect of an individual. For example, if a population or sample consists of people then the variable could be weight, height, color of eyes, gender, etc.
DATA: The possible observations or outcomes for a variable concerning individuals.
CHARCTERISTIC: A summary of a numerical variable of a population or sample such as mean, max, range or variance. Label data can not be summarized. DEFINITIONS
DEFINITIONS DATA CONSISTS OF LABELS: Colors, Judgments, Grades (as is A, B, C, D, F), Names.
DATA CONSISTS OF NUMBERS FROM MEASUREMENTS OR COUNTS: Weights, Polls, Surveys, Temperatures, Lengths. DEFINITIONS
DEFINITIONS Characteristics that come from the POPULATION are called PARAMETERS.
Characteristics that come from a SAMPLE are called STATISTICS.
If the data comes from labels then not called either (as no numerical summary is possible for Qualitative data). DEFINITIONS
DEFINITIONS QUALITATIVE DATA comes from LABELS.
QUANTITATIVE DATA comes from NUMERICAL data DEFINITIONS
DEFINITIONS DISCRETE DATA comes from counts and are whole numbers (have no decimal parts).
CONTINUOUS DATA comes from measurements and are real numbers (may have decimal parts)
NOTE: LABELS are neither DEFINITIONS
DEFINITIONS TWO METHODS OF OBTAINING DATA: OBSERVATION: Data from observing, only. Not interfering with the process in any way.
EXPERIMENTATION: Data from controlling some factors of a process. Often involves comparing results of two or more control factors. SHOW HANDOUT
Also See Page 10 of Text for Description of Levels of Measurement SPECIAL NOTE
SPECIAL The data you collect is not the answer to the question you are investigating.
The data you collect is the result of the question you ask or the instructions you give.
Examples THIS SEMESTES LABS
THIS Last summer I was concerned because of the large proportion of As my classes were getting.
I asked my coordinator about it and she said not to be concerned because it was summer.
I want to investigate her contention that summer classes do better than spring classes.
See data from Spring, 2011 and Summer 2010 TYPES OF SAMPLING
TYPES Simple Random Sampling
See section 1.4 for complete discussion of other sampling types BIAS IN SAMPLING
BIAS Always Avoid Bias
Two Types: Intentional and Unintentional
See 1.5 for complete discussion EXPERIMETAL TYPES
EXPERIMETAL CONTROL FACTORS
DOUBLE BLIND STUDIES ...
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- Fall '12
- Math, The Conclusion, Soft water