Cheatography

# AP Statistics Unit 1 Cheat Sheet by kayheartsuu

AP Statistics Unit 1 Study Guide

### Terms to Know

 Population entire collection of indivi­duals or objects that inform­ation is gathered from Sample subsets of population that is randomly selected Census performed to gather inform­ation about an entire population Descri­ptive Statistics method of organizing and summar­izing data Infere­ntial Statistics making genera­liz­ations from a sample to a population Variable charac­ter­istics that make change Data actual observ­ations collected Catego­rical Variable no meaningful numerical value Numerical Variable measur­ements, can be averaged Discrete Numerical can only be specific values Continuous Numerical can be any value Univariate describes single charac­ter­istics Symmet­rical Distri­bution both sides of data are approx­imately the same when folded down the middle Normal Distri­bution bell-s­haped, occurs a lot in real life Uniform Distri­bution rectan­gular shaped Skewed Distri­bution one side is longer than the other Bimodal has two distinct maximums Parameter a fixed value about a popula­tion; typically unkown Statistic a value calculated from a sample that is used to estimate the parameter Median the middle of the data; 50th percentile Mean the arithmetic average Mode the observ­ation that occurs the most often Resistant when a statistic is not affected by outliers Variab­ility how spread out the data is Standard Deviation a measure of the average distance from the mean Interq­uartile Range the range of the middle 50% of the data Variance the average of the squared deviations

### SOCCS

 Shape the distri­bution of the graph (symme­trical, uniform, normal, skewed, bimodal) Outliers values that are away from the rest of the data Context explain what the graph is showing Center describe the mean or median of the data Spread describe the range, IQR, or standard deviation of the data

### Graph Types

 Bar Graph catego­rical, bars do not touch Pie Graph catego­rical, percen­tages, can be approx­imated Dotplot numerical, putting dots on a number line Stem Plot univariate numerical, must have a key Discrete Histograms numerical, bars touch, centered over discrete values Continuous Histograms numerical, bars touch, bars cover an intervals of values Boxplot displays percen­tages of data, constr­uction is subjec­tive, useful for compar­isons Ogives shows relative frequency, or percen­tiles for data

### Formulas

 Z-Score Z = (value - mean)/­(st­andard deviation) IQR Q3 - Q1 Lower Fence Q1 - 1.5(IQR) Upper Fence Q3 - 1.5(IQR)