| A | B |
|---|
| population | the entire group of objects or individuals considered for a survey |
| sample | a part of the population |
| biased sample | a sample that does not fairly represent the population |
| random sample | a sample in which each individual or object in the entire population has an equal chance of being chosen |
| systematic sample | a sample of a population that has been selected using a pattern |
| stratified sample | a sample of a population that has been divided into subgroups |
| stem-and-leaf plot | a graph used to organize and display data so that the frequencies can be compared |
| back-to-back stem-and-leaf plot | a stem-and-leaf plot that compares two sets of data by displaying one set of data to the left of the stem and the other to the right |
| mean | the sum of a set of data divided by the number of items in the data set; also called average |
| median | the middle number, or the mean of the two middle numbers, in an ordered set of data |
| mode | the number or numbers that occur most frequently in a set of data |
| variability | the spread of values in a set of data |
| range | the difference between the greatest and the least values in a data set |
| quartile | three values, one of which is the median, that divide a data set into fourths |
| box-and-whisker plot | a graph that displays the highest and lowest quarters of data as whiskers, the middle two quarters of data as a box, and the median |
| bar graph | a graph that uses vertical or horizontal bars to display data |
| frequency table | a table that lists items together according to the number of times that the items occur |
| histogram | a bar graph that shows the frequency of data within equal intervals |
| line graph | a graph that uses line segments to show how data changes |
| scatter plot | a graph with points plotted to show a possible relationship between two sets of data |
| correlation | the description of the relationship between two data sets |
| line of best fit | a straight line that comes closest to the points on a scatter plot |
