# Links: Stat 202 Fall 2015

From Sean_Carver

## Contents

## Links

- Kahn Academy videos on why you divide by (n-1) instead of (n) when you compute the sample standard deviation or sample variance. Video 1: https://www.khanacademy.org/math/probability/descriptive-statistics/variance_std_deviation/v/review-and-intuition-why-we-divide-by-n-1-for-the-unbiased-sample-variance Video 2: https://www.khanacademy.org/math/probability/descriptive-statistics/variance_std_deviation/v/simulation-showing-bias-in-sample-variance
- How to interpret a Normal Quantile Plot (QQ-Plot): http://stats.stackexchange.com/questions/101274/how-to-interpret-a-qq-plot
- Comparison of Normal and T Distributions

## Practice Exams And Exams

## StatCrunch Skills We Have Learned Before Summer 2015 Midterm

### StatCrunch Plots We Have Learned Before Summer 2015 Midterm

- Bar Graph
- Pie Chart
- Stemplot
- Histogram
- QQ-Plot (Normal Quantile Plot)
- Scatter Plot
- Scatter Plot with Regression Line overlaid
- Residual Plot
- Boxplot

### StatCrunch Calculators We Have Learned Before Summer 2015 Midterm

- Normal Calculator
- Binomial Calculator

### StatCrunch Statistics We Have Learned Before Summer 2015 Midterm

- Summary Stats (Columns)
- Summary Stats (Correlation)
- Regression (Simple Linear)

### Other Skills We Have Learned Before Summer 2015 Midterm

- Load Data
- Delete and Insert Rows And Columns
- Rename Columns
- Simulate Data From A Specified Distribution
- Use Fixed and Dynamic Seeds
- Apply Transformations to Data

## StatCrunch Skills We Have Learned *After* the Summer 2015 Midterm

### Sampling

- Conduct a random sample of data
- Sample if there is more than one column and you want sampled columns to correspond.
- Use fixed seeds for sampling
- Generate a sequence of numbers to use for sampling.

### Hypothesis Testing

- Z-Test
- T-Test
- Proportion Test
- One Sample
- Two Sample
- Paired
- With Data
- With Summary

### Confidence Intervals

- Z-Stats
- T-Stats
- Proportion Stats
- One Sample
- Two Sample
- Paired
- With Data
- With Summary

### Power/Sample Size

- Z-Stats
- T-Stats
- Proportion Stats
- One Sample
- Two Sample