This document discusses key concepts in statistics including population, sample, qualitative and quantitative data, histograms, opinion surveys, and circle graphs. A population is the overall group being studied, while a sample is a subset of the population that is actually surveyed. Qualitative data falls into categories while quantitative data is numerical. Histograms display quantitative data intervals as bars and circle graphs illustrate parts of a whole using percentages. Opinion surveys collect data based on opinions.
![Inv #6.notebook
*histogram - displays quantitative data in adjacent intervals,
represented by bars that touch
*opinion survey - a type of survey conducted to collect data
based on an opinion
*circle graph (pie graph) - often used to display qualitative data
and is used to illustrate parts of a whole [percents]
January 23, 2014](https://image.slidesharecdn.com/7thprealg-inv6-140123134755-phpapp02/85/7th-pre-alg-inv-6-2-320.jpg)