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7-2 Organizing and Displaying Data p. 326 (ex.1) Frequency table - a table that lists each item in a data set with the number of times the item occurs. - Make a tally mark for each item - The number of tally marks in each row is the frequency. Use numbers to indicate the frequency. p. 327 (ex. 2) Line plot - a graph that shows the shape of a data set by stacking X's above each data value on a number line. - Draw a line horizontally with the numbers representing the data range below it. - Place an "X" above each data value to represent the given data. p. 327 (ex. 3) Range - the difference between the least and greatest values in a set of data. - Subtract the least from the greatest value in a set of data.
7-4 Bar Graphs and Line Graphs p. 335 (ex. 1) Bar graph - a graph that uses vertical or horizontal bars to display numerical information. (Use bar graphs to compare amounts.) - Components of a bar graph: - Choose an appropriate title - Draw and label the horizontal and vertical axes - Choose a scale for the data (0 - ?) [along the vertical axis for vertical bars] [along the horizontal axis for horizontal bars] - Draw bars of equal widths (The heights will vary depending on the data set.) - Label each bar p. 336 (ex. 2) Histogram - a bar graph that shows the frequency of each data item. - Histograms often combine data into equal-sized intervals (ranges) - There is no space between the bars - Each bar represents an interval rather than an individual number or item - Often it is helpful to make a frequency table before generating the histogram. (This table will make it easier to determine the intervals.) - Use the same components as a bar graph to create the histogam. p. 336 (ex. 3) Line graph - a graph that uses a series of line segments to show changes in data. (Line graphs usually show changes over time.) - Components of a line graph: - Choose an appropriate title - Choose a scale for the "y" axis. Determine the range for the data and decide on the intervals. (5, 10, etc.) - Draw and label both axes. - Plot a point for each data item. Then connect the points with straight line segments.
7-5 Circle Graphs p. 342 (ex. 1) Circle graph - a graph of data where the entire circle represents the whole. Each wedge of the circle represents part of the whole. p. 342 (ex. 2) Making a circle graph. - Determine the total - Change the data to percents of the total (Round to the nearest percent.) - Use number sense to divide the circle - Give the graph a title - Label the divided circle with each percent (A different color can also be used.) - Provide a key for your graph *See p. 341 "Investigation box" for creating something more precise.