Chapter 1 Flashcards
Population
- The collection of all elements
- Represented by “N”
Sample
-Subset of a population
-Noted by “n”
Parameter
- A characteristic of a population (mean standard deviation etc.)
Statistics
- A measurement derived from sample data
Inferential Statistics
- Using sample statistics to draw inferences about parameters
Descriptive Statistics
Qualitative Data
- Categorical responses
Quantitative Data
- Results in numbers
Discrete data
- Quantitative
- Results in whole numbers
Continuous data
- Quantitative
- Results in integers
Central location
- Mean, Median, Mode
Measures of Varitibility
- Range, Variance, Standard Deviation,
Sample Variance
- S^2= sum of(x-xbar)^2/(n-1)
Population Variance
- S^2= sum of(x-xbar)^2/(N)
Sample Standard Deviation
- S= sqrt(sum of(x-xbar)^2/(n-1))
Population Standard Deviation
- S= sqrt(sum of(x-xbar)^2/(N))
Relative Position of Data
- Percentile Rank, Percentile, Quartile
How to calculate percentile
I= (Percentile Rank/100)*samplesize
How to calculate percentile rank
(Number of values below or equal to the number)/(Total number of values in the set) * 100%
Five number summary
[xmin, Q1, Q2(median), Q3, xmax]
Z-scores
- Way to locate if data is above or below average
Sample z-score
Z=(x-xbar)/(sample standard deviation)
Population z-score
Z=(x-xbar)/(population standard deviation)
Find values from z scores
-Sample: Value= xbar + z-scoresample standard deviation
-Population: Vaule= xbar +z-scorepopulation standard deviation
