More Graphs — But What Type Are These?

 Divide the range of data into equal widths.  Every number can only be placed in one class (bar).  Using the count of the data on the y-axis is called a frequency histogram.  Using the percentage of the data on the y- axis is called a relative frequency histogram.

 SYMMETRIC: Right and left sides are roughly the same.  SKEWED RIGHT: Most of the data is on the left, tail is on the right.  SKEWED LEFT: Most of the data is on the right, tail is on the left.  UNIFORM: All bars are roughly the same height.

STEM PLOTS 1. The stem includes all of the digits of the number except for the final digit. 2. The leaf is the last digit of the number. 3. A line divides the stem from the leaves. 4. A key is needed to interpret the stemplot ’ s definition.

DOT PLOTS 1. Number the horizont al axis evenly. 2. All data is represen ted by a dot on the graph. 3. Any duplicat es have an addition al dot drawn above the previous one. 4. Can also be interpre ted by its shape.

 An ogive is a connected line graph which demonstrates the cumulative increase in value of the y-axis variable as the x-axis variable increases.  The y variable values are cumulative, adding to the previous values, until they reach the maximum possible value, or 100% (1.0).  Is this a qualitative graph or quantitative graph? How do you know?

 Graph which shows data collected at regular intervals (hourly, daily, monthly, yearly) in order to looks for trends.  X-axis represents time, Y-axis represents variable being measured (such as stock prices or unemployment rates).  What type of graph is this?

 A type of line graph which uses line segments connected to points located directly above class midpoint values.  This can be used for frequency or relative frequency graphs (shown on the y-axis).  Which type of graph is this?

 A Pareto chart is a bar graph which has its bars arranged from largest to smallest.  The y-axis will be labeled for frequencies or relative frequencies.  By arranging the bars in this manner, the bar(s) with the highest frequency get the most attention.  Which type of graph is this?

 Scatter plots are graphs of ordered pair points (x, y) which represent data which may (or may not) have a relationship.  Each axis represents a variable.  The scatter plot is usually judged by its strength of correlation (whether its points are close together) and the direction the points are facing.  What type of graph is this?

 Who can name all the qualitative graphs we’ve discussed in this chapter so far?  Bar Graph, Pareto Chart, Pictogram, Pie Chart  Who can name all the quantitative graphs we’ve discussed in this chapter so far?  Histogram, Stem Plot, Dot Plot, Time Series Plot, Ogive, Scatter Plot, Frequency Polygon, Line Graph