1. CO_02.jpg

2. 2.2 Graphs and Tables for Quantitative Data Objectives: By the end of this section, I will be able to… 1) Construct and interpret a frequency distribution and a relative frequency distribution for quantitative data. 2) Use histograms and frequency polygons to summarize quantitative data.

3. Section 2.2 Graphs and Tables for QUANTITATIVE Data

4. We need DATA What are the ages of your siblings?

5. SORT DATA First thing we want to do is plug the data into our calculators (STAT – EDIT – LIST1) Then Sort your data (STAT – SORTA() – 2 nd 1 – ENTER)

6. Frequency Distribution Is a table that organizes data. Class #IntervalClass Midpoint Freq.Relative Freq

7. Frequency Distribution Step 1: Determine how many classes Step 2: Determine the CLASS WIDTH 1) find the RANGE of data 2) Divide RANGE by # of classes 3) Round the answer Step 3: Determine the upper and lower class limits

8. Frequency Distribution Fill out the Table Class #IntervalClass Midpoint Freq.Relative Freq

9. Histogram uses INTERVALS Has TOUCHING BARS Its NOT a bar graph

10. Histogram Create a histogram by hand Label all your axes Make the bars touching! x axis = ages of siblings y axis = frequency

12. On the calculator Now let’s graph a histogram on the calculator

16. Distribution Shape We need to analyze the shape of the graphs. There are two types of shapes. Symmetric Skewed

17. Distribution Shape Symmetric: if there is a line that splits the graph in half so that one side is a mirror image of the other The Bell Shaped Curve is a great example of a symmetric graph.

18. Distribution Shape Skewness: when a graph has a longer tail on one side –Left skewed vs. right skewed

19. Frequency Polygon Uses dots to plot the CLASS MIDPOINTS It is NOT a line graph Can be found in the financial section of newspapers/internet

20. Frequency Polygon Create a frequency polygon by hand Label all your axes Connect your dots! x axis = ages of siblings y axis = frequency