1 / 30

Warm-up

Warm-up. *Finish the Titanic Activity!. Numerical Graphs. Graphs to use for Quantitative Data. Section 1.2 Analyzing Numerical Data. Learning Objectives. After this section, you should be able to… DESCRIBE numerical graphs CONSTRUCT & INTERPRET dot plots CONSTRUCT & INTERPRET stem-plots.

kent
Download Presentation

Warm-up

An Image/Link below is provided (as is) to download presentation 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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Warm-up *Finish the Titanic Activity!

  2. Numerical Graphs Graphs to use for Quantitative Data

  3. Section 1.2Analyzing Numerical Data Learning Objectives After this section, you should be able to… • DESCRIBE numerical graphs • CONSTRUCT & INTERPRET dot plots • CONSTRUCT & INTERPRET stem-plots

  4. Describing a Graph • There’s a general strategy for interpreting graphs of quantitative data. • Look for the overall pattern and for striking departures from that pattern.

  5. Describing a Graph – Numerical Graphs Only!!!!! • Overall Pattern Described by: a) Shape b) Center c) Spread • Departure Described by: Outlier Outlier – An individual value that falls outside the overall pattern. Don’t forget your SOCS!

  6. Center If you had to pick a single number to describe all the data – the center would be the best. It’s in the middle!

  7. Shape Description Concentrate on Main Features: • Look for Major Peaks – not minor ups and downs • Look for clusters and obvious gaps • Look for possible outliers • Look for symmetry or skewness

  8. Shape – Are there modes? Bimodal Unimodal How many bumps are in the graph? – Those are modes.

  9. UNIMODAL – A Distribution that has 1 mode.

  10. BIMODAL – A Distribution that has 2 modes.

  11. UNIFORM –Doesn’t appear to have any mode. All bars are approximately the same height. Remember – it will not ALWAYS be EXACTLY the same frequencies, but they will be very close.

  12. Symmetric? Can you fold it along a vertical line through the middle and have the edges math pretty closely? If so, then it’s symmetric. Bell-Shaped

  13. Shape –Skewed? It’s skewed to the side of the longer tail. Negatively Skewed or (Skewed left) Positively Skewed or (Skewed right)

  14. For his own safety, which way should he go “skewing?” Left of Course!

  15. Shape – Unusual Features • Are there any stragglers, or outliers? • Are there any gaps?

  16. Spread – (Variation) • How spread out is the data? • How spread out is the interquartile range? • Is it tightly clustered around the center or spread out? (What is the Range?) (We will learn more about this later……..)

  17. We looked at the base salaries of the CEOs of the 800 largest corporations in 1994. • Center – Centered around $500,000 • Shape – Unimodal, Nearly Symmetric, Some high outliers • Spread – Majority are between $100,000 and 1,000,000. But there are a few with salaries between $2,500,000 and $3,000,000

  18. Displaying Quantitative Data • Dotplots • One of the simplest graphs to construct and interpret is a dotplot. Each data value is shown as a dot above its location on a number line. How to Make a Dotplot • Draw a horizontal axis (a number line) and label it with the variable name. • Scale the axis from the minimum to the maximum value. • Mark a dot above the location on the horizontal axis corresponding to each data value.

  19. EPA Estimate of Hwy Gas Mileage (mpg) for 24 2009 midsize cars. Describe the shape, center, and spread of the distribution.

  20. There are 3 clusters of values: cars that get 25 mpg, 28 – 30 mpg, and 33 mpg. • Large Gaps between 22 mpg, 18 mpg, and 14 mpg. • The center is about 28 mpg. (A typical 2009 model gets 28 mpg) • Spread: Highest value is 33 mpg. Lowest value is 14 mpg. Range = 19 mpg. • Outliers: There are 2 cars with unusually low gas mileage ratings. These cars are possible outliers.

  21. Dotplots How many keys are on your keychain?

  22. Dotplots – You Try one! The following data give the number of hurricanes that happened each year from 1944 through 1969. 3, 2, 1, 2, 4, 3, 7, 2, 3, 3, 2, 5, 2, 2, 4, 2, 2, 6, 0, 2, 5, 1, 3, 1, 0, 3

  23. Displaying Quantitative Data • Stemplots (Stem-and-Leaf Plots) • These data represent the responses of 20 female AP Statistics students to the question, “How many pairs of shoes do you have?” Construct a stemplot. Key: 4|9 represents a female student who reported having 49 pairs of shoes. 1 93335 2 664233 3 1840 4 9 5 0701 1 33359 2 233466 3 0148 4 9 5 0017 1 2 3 4 5 Stems Add leaves Order leaves Add a key

  24. Stemplot – (Stem & Leaf) – Let’s find our pulse rates.

  25. What’s your height? Compare. Male Female

  26. Sometimes we have to truncate the data.

  27. Grade Point Average

  28. Reaction Times Activity

  29. Make & Describe a Stemplot 229 247 347 246 198 260 320 360 414 214 218 276 197 406 261 347 223 196 202 628

  30. Homework • Page 43 ( 37 - 49)odd

More Related