role of statistician - answer1. Design Studies
2. Analyze Data
3. Translate data into knowledge and understanding of the world around us
descriptive statistics - answer organizing and summarizing data
inferential statistics - answer formal methods for drawing conclusions from data
probability - answer mathematical study of uncertainty- foundation of statistics
population - answer all individuals, objects, or things whose properties are being studied
parameter - answer a number that is used to represent a characteristic of the population
and that generally cannot be determined easily
sample - answer a subset of the population of interest that we will collect data on
representative sample - answer a subset of the population that has the same
characteristics as the population of interest
statistic - answer- a number that represents the property of interest in the sample
- an estimate of the parameter value that we get looking only at the sample
parameter is to population as statistic is to sample - answerwe use the statistic,
calculated from data obtained from a sample, in order to estimate the parameter which
is unknown
1. Have parameter that you are interested in learning about for some population
2. Obtain a sample from the pop.
3. Gather data on that sample
4. Calculate a statistic
5. Use the statistic as an estimate of the parameter
variable - answer- a characteristic or measurement that can be determined for each
member of a population
- 2 types
numerical/quantitative variable - answer- take on a number value of units
- discrete: measured in whole units (count data)
- continuous: can be measured in decimals (time to finish a race)
, categorical/qualitative variable - answer- take on a label
- nominal: no natural order to the variables (ethnicity)
- ordinal: is a natural order to variables ( movie reviews)
Identify population, statistic, parameter, sample, variable, & data:
We want to know the average (mean) amount of money spent on school uniforms each
year by families with kids at Knoll Academy. We randomly survey 100 families with kids
in the school. Three families spent $65, $75, and $95, respectively - answer-
Population: families whose kids attend Knoll Academy
- Statistic: mean amount of $ spent on uniforms
- Parameter: price spent on school uniform
- Sample: 100 families w/ kids at school
- Variable: amount of $ spent
- Data: $65, $75, $95...
Determine correct data type:
1. number of pairs of shoes you own
2. type of car you drive
3. distance from home to nearest grocery store
4. number of classes you take per school year
5. type of calculator you use
6. weights of sumo wrestlers
7. number of correct answers on a quiz
8. IQ scores - answer1. quantitative discrete
2. categorical
3. quantitative continuous
4. quantitative discrete
5. categorical
6. quantitative continuous
7. quantitative discrete
8. quantitative discrete
pie chart - answer- categories of data are represented by wedges in a circle and are
proportional in size to the percent of individuals in each category
- displaying parts of a whole, cannot add up to be more than 100%
bar graph - answerthe length of the bar for each category is proportional to the number
or percent of individuals in each category. bars may be vertical or horizontal
methods of random sampling - answer1. simple random sample (srs)
2. systematic sample
3. stratified sample
4. cluster sample
simple random sample (SRS) - answer- every member of the population has an equal
chance of being chosen
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