Statistics
- Deals with the collection, analysis, interpretation, and presentation of data
Probability
- Mathematical tool used to study randomness
Key Terms
- Population
- Parameter
- Sample
- Statistic
- Variable
- Data
Types of Data
Quantitative- a number
- Discrete (You count it)
- Continuous (You measure it)
Qualitative- A category (words)
Sampling with Replacement
- A member of the population may be chosen more than once
Sampling without Replacement
- A member of the population may be chosen only once
Random Sampling
- Each member of the population has an equal chance of being selected
Sampling Methods
Random- Simple random sample
- Stratified sample
- Cluster sample
- Systematic sample
Not Random- Convenience Sample
Note:
Samples must be representative of the population from which they come. They must have the same characteristics. However, they may vary but still represent the same population
Frequency, Relative Frequency, and Cumulative Relative Frequency
Frequency (freq. or F)- The number of times an answer occurs
Relative Frequency (rel. freq. or RF)- The proportion of times an answer occurs
- Can be interpreted as a fraction, decimal, or percent
Cumulative Relative Frequencies (cum. rel. freq. or cum RF)- An accumulation of the previous relative frequencies