Histograms - Part #2 - Types of Histograms

Line Graph

* a line graph presents data so that changes and trends over time can be identified and a comparisons can be made. *use when you have ongoing data * used when you want to show changes over time.

Line Plot

* a line plot shows the frequency of data values. The range determines the # of lines. The x's represent the data value. * useful when finding the range (value points) * Mode, mean, median set of data. * easy to identify outliers and clusters. * an outlier is a piece of data that is set far apart from the rest of the data. * a cluster is where data tends to group together. * best to use when you have a small range.

Pictograph

* a pictograph presents data using pictures or symbols * each picture or symbol represents and assigned amount of data * Use when you only have 2-6 categories * the key tells the # that each picture or symbol represents. Use when you have large amounts of data that is to big for a bar graph.

Pie Graph

* a pie graph shows how parts are related to the whole. * use when you want to show how a total amount of data is divided into parts. *can be used to show % * use when you have 3-7 categories

Stem-and-Leaf plot (stemplot)

* a special talbe where each data value is split into a "stem" and a "leaf" plot. * the "stem" is the first digit and the leaf is the last digit in a value. * useful when organizing numerical data * in the picture 72 for a grade would be represented with the stem being 7 (which represents 70) and the leaf part would be 2. * in the example there is a grade of 72, 72, 74, 75, 76, 79 that is represented on the first row of the stemplot

Bar Graph (Histogram)

a bar graph presents data so that comparisons of different items can be made. * it is used to compare the frequency of data. * use a bar graph when you want to compare 2 or more sets of data.