Chapter 5 sections 5 c and 5d
- 1. Chapter 5 – Section D Charts / Graphs Used in the Media
- 2. Ways to Display Statistical Data • Long papers and paragraphs – Not the best way • Tables • Graphs and Charts
- 3. Frequency Table • Contains two columns – A category – A frequency (a total, a percent, or a fraction) Grade Frequency Cumul. A 5 5 B 10 15 C 3 18 Below C 2 20 Grade Frequency Cumul. 90 -99 8 8 80 – 89 10 18 70 – 79 7 25 The grouping of numbers is called a BIN
- 4. Another Frequency Table Movie Reviews for “Harry Potter” Rating Frequency Relative Frequency Cumulative Frequency * * * 5 5/ 10 = 50% 5 * * 3 3 / 10 = 30% 5+ 3 = 8 * 2 2 / 10 = 20% 5 + 3 + 2 = 10 Total: 10 Total: 100%
- 5. All Graphs and Charts Should Have: • A title or caption – Describes what is being shown and (possibly) the source of the data • A horizontal scale and title – This shows the categories of the data • A vertical scale or title – This shows the numbers on the scale • A legend (usually a color scheme) – This indicates what each color represents
- 6. • Qualitative Data – Deals with descriptions – Can be observed and is “non-numerical” – Based on “quality” (color, appearance, rating, etc.) • Quantitative Data – Deals with numbers – Can be measured and/or counted – Based on “quantity” (weight, cost, ages, etc.) • Be careful: Just because data is represented by “a number” does not automatically make it “quantitative” The Data “Categories ” or “Types”
- 7. • Marital status of hospital nurses • Colors of cars in CCC parking lot • A person’s movie rating(four stars, three stars) • Ethnicity (Black, Latino, White) • Level of education (high school, college) • Political party preference Qualitative Data Examples
- 8. • Time it takes to run a kilometer • Weight of lobsters in a tank at a restaurant • Ounces of fruit in a smoothie • Seating capacity of football stadium • Age of people living in nursing home • Number of people jailed for drug possession Quantitative Data Examples
- 9. Bar Chart, Pie Chart Both are used to show qualitative data The bars should have “spaces” between them. The pie chart percentages should always add up to 100% (with rounding off)
- 10. Histogram and Line Chart Both are used to show quantitative data The widths of the bars represent “bin ranges” – therefore the bars should touch each other.
- 11. The Multiple Bar Graph • Contains two sets of bars • Used to compare two sets of data
- 12. The Stack Plot • The “thickness” determines the data value • Use “subtraction” and “totals” in this graph
- 13. Geographic Data • Uses a map to display data • Use the legend to determine information
- 14. 3 – D Graphs • “Should” represent three pieces of information • Be careful: Some 3-D graphs only show “two” pieces of info -- and should be 2-dimensional!
- 15. Pictographs • Often embellished with artwork to make the display more attractive / attracting
- 16. Combination Graphs These graphs can combine pie charts, bar charts, line charts, and data into a graph that can be very complex.
- 17. Careful When Reading Graphs / Charts • Graphic (picture size) is often distorted and creates incorrect conclusions • Watch the number scale (Should it begin at zero?) • Don’t be distracted by the “cosmetic touch”
- 18. To represent qualitative data • Use a bar chart • Use a pie chart • Both should contain the following: – A title – Vertical and horizontal scales and titles – A legend (tells what each color represents)
- 19. To represent quantitative data • Use a histogram • Use a line chart