Statistics -
Science of collecting, organizing, summarizing and analyzing information. You draw conclusions and/or answer questions.
Data -
Fact or proposition used to draw conclusion or make a decision.
numerical:
Height, weight, etc...
non-numerical:
Gender, blood type, color, etc...
Population -
Entire group of individuals being studied.
Individual -
A person or object thats a member of the population
Sample -
Subset of population
Statistic -
Numerical summary of a sample
A. Descriptive statistics -
Consists of organizing and summarizing data
a. Numerical summaries
b. Tables
c. Graphs
B. Inferential statistics -
Uses methods which take a result from a sample, extend it to a population and measure the reliability of the result.
7. Parameter -
Numerical summary of a population
Ex) Determine whether the underlined value is a parameter or statistic.
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18. Only 12 men have walked on the moon. The average age of these men at the time of their moonwalks was 39 years, 11 months, 15 days.
Parameter
Only 12 men have walked on the moon.
Numerical description of a population characteristic.
20. Telephone interviews of 1,502 adults 18 years of age or older, conducted nationwide February 1-13, 2007, found that only 69% could identify the current vice-president.
Statistic
Not ALL.
A numerical description of a sample characteristic.
8. Process of Statistics -
a. Identify the research objective
b. Collect data
c. Describe data
d. Make inferences- apply techniques to extend results from sample to the population.
9. Variables -
Characteristic of the inividuals with in a population.
A. Qualitative (Categorical) -
Allows for classification of individuals based on some attribute or characteristic.
B. Quantitative -
(Numerical) Measures of individuals.
a. Discrete variable -
Finite # or countable # of possible values.
ex.) # of children in family
# of T.V.s in a household
b. Continuous variable -
Infinite # of possible values NOT countable.
Obtained by MEASURING.
ex.) Temperature
Ex) Classify the variable as qualitative or quantitative.
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21. Nation of origin
Qualitative
22. Number of siblings
Quantitative
25. Number of unpopped kernels in a bag of ACT microwave popcorn
Quantitative
27. Phone number
Qualitative
Ex) Determine whether the quantitative variable is discrete or continuous.
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29. Runs scored in a season by Albert Pujols
Discrete
31. Length (in minutes) of a country song
Continuous
32. Number of sequoia trees in a randomly selected acre of Yosemite National Park
Discrete
33. Temperature on a randomly selected day in Memphis, Tennessee
Continuous
10. 4 levels of measurement
...
A. Nominal -
Name, label, category, etc...
NO order or ranking
ex.) zip code, gender, eye color
B. Ordinal -
Can be arranged in order or ranked
NO difference in the ranks
ex.) Scale: Poor, Good, Excellent
Grade: A,B,C,D,E...
C. Interval -
Ranks data (+ or-)
Difference in values have meaning
No meaningful zero
ex.) SAT score
IQ -> 109 IQ different from 129 IQ, b/c 129 IQ is 20points more than 109.
ex.) Temperature- 0 degrees does not mean no heat. Not meaningful.
D. Ratio-
Ratio of values HAVE meaning. (* or /)
Value of zero means the absence of quantity.
ex.) Height, weight, time, age
Zero lb. really means no weight!
Ex) Determine the level of measurement of each variable.
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37. Nation of origin
Nominal
38. Movie ratings of one star through five stars
Ordinal
39. Volume of water used by a household in a day
Ratio
40. Year of birth of college students
Interval
41. Highest degree conferred ( high school, bachelor's, and so on)
Ordinal
42. Eye color
Nominal
43. Assessed value of a house
Ratio
44. Time of day measured in military time
Interval b/c military time has no zero