Moral of the story, hire someone to help with this.
Descriptive Statistics
- Almost all studies need descriptive statistics
- Parameters
- Demographics, salary schedules, etc. can all be statistics
- Descriptive research is a type of descriptive statistics
- Numerical Data - Numbers
- SAT, ACT scores, temperatures, Money spent on sports equipment
- Categorical Data
- Percent minority, percent male, etc
Summarizing Data
- Percent minority, percent male, etc
- Distribution - how data are distributed. Visual representation of the data
- Frequency Polygons - looks like a line graph
- Positively skewed polygon - trails off in a positive direction
- Negatively Skewed polygon - trails off in a negative direction
- Histogram - Bar graph
- Normal distribution - symmetrical
- Averages - all the same on a normal curve
- Mode - most frequent number
- Median - middle one
- Mean - average
- CleanShot 2024-02-27 at 19.02.40@2x.png
- Measures of central tendency
- Mean can be the same, but different spread or different mean.
- Range - high and low
- 5 number summaries - box plot
- Standard Deviation - 1 sd is ameasure of how spread out the thing is.
- 3 standard deviations is 99%
- 68% fall within the 1 standard deviation
Stem-Leaf Plots
display that organizes a set of data to show both its shape and its distribution Take the results, put the tens in one column and the ones in the other column.
Correlation Does Not Equal Causation
- Scatterplot - relationship between two quantitative variable
- Outliers - unusual exception
- Pearson’s R R=1 is perfect correlation, 0 is no correlation -1 is perfect negative correlation