Section 2.2

1 / 24

Section 2.2 - PowerPoint PPT Presentation

Section 2.2. More Graphs and Displays. Stem-and-Leaf Plots. Each number is separated into a STEM and LEAF component. The STEM is the leftmost digit(s). The LEAF is the rightmost digit. It’s important to include a key to identify values. For example… Key: 15 | 5 = 155.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Section 2.2

More Graphs and Displays

Stem-and-Leaf Plots
• Each number is separated into a STEM and LEAF component.
• The STEM is the leftmost digit(s).
• The LEAF is the rightmost digit.
• It’s important to include a key to identify values. For example… Key: 15 | 5 = 155
Make a stem-and-leaf plot:
• Ages of the top 30 highest paid CEOs (Forbes Magazine).
Pie Chart (for Qualitative Data)
• A circle divided into sectors that represent categories.
• The area of each sector is proportional to the frequency of the category.
• Find RELATIVE Frequency and multiply by 360o to get the central angle for each category.
Use a Pie Chart to display data
• 2010 NASA budget request (in millions of dollars)
Pareto Chart (for Qualitative Data)
• Vertical bar graph in which the height of each bar represents the frequency or relative frequency.
• Bars are positioned in order of decreasing height, left to right.
• EX: Make a Pareto chart
• Ultraviolet indices for 5 cities at noon:
Scatter Plot (for Paired Data Sets)
• Paired data  Ordered pairs.
• Plot on a coordinate plane.
• Independent variable on the x-axis.
Section 2.3

Measures of Central Tendency

Measure of Central Tendency:
• A value that represents a typical, or central, entry of a data set.
• 3 most common are MEAN, MEDIAN, and MODE
MEDIAN
• The data entry in the MIDDLE.
• List data from least to greatest.
• Find the middle value.
• (For even n, find the average of the 2 middle values)
MODE
• Data entry that occurs MOST often (highest frequency)
• A data set may have no mode or have more than mode.
• BIMODAL = 2 modes.
Shapes of Distributions
• Distributions may look ..
• Symmetric
• Uniform
• Skewed Left
• Skewed Right