# SECTION 2.1 - Section 2.1 Categorical Variables Statistics...

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Statistics: Unlocking the Power of Data Lock 5 Section 2.1 Categorical Variables
Statistics: Unlocking the Power of Data Lock 5 Outline One categorical variable Summary statistics: frequency table, proportion Visualization: bar chart, pie chart Two categorical variables Summary statistics: two-way table, difference in proportions Visualization: segmented or side-by-side bar chart
Statistics: Unlocking the Power of Data Lock 5 The Big Picture Population Sample Sampling Statistical Inference Descriptive Statistics
Statistics: Unlocking the Power of Data Lock 5 Descriptive Statistics In order to make sense of data, we need ways to summarize and visualize it Summarizing and visualizing variables and relationships between two variables is often known as descriptive statistics (also known as exploratory data analysis ) Type of summary statistics and visualization methods depend on the type of variable(s) being analyzed (categorical or quantitative)
Statistics: Unlocking the Power of Data Lock 5 One Categorical Variable A random sample of US adults in 2012 were surveyed regarding the type of cell phone owned Android? iPhone? Blackberry? Non- smartphone? No cell phone?
Statistics: Unlocking the Power of Data Lock 5 Frequency Table A frequency table shows the number of cases that fall in each category: Android 458 iPhone 437 Blackberry 141 Non Smartphone 924 No cell phone 293 Total 2253
Statistics: Unlocking the Power of Data Lock 5 Proportion
Statistics: Unlocking the Power of Data Lock 5