Frequency Tables number of times something occurs STEPS to making a frequency table: 1) CHOOSE INTERVAL SIZE Note: 2) USE A TALLY MARK 3) WRITE THE FREQUENCY Example #1 In the United States, hurricane season starts June 1 and lasts about 26 weeks. Meteorologists record the number of weeks into the season each hurricane occurs. The number of weeks into the hurricane season in which Atlantic hurricanes occurred from 1997 to 2000 are listed below. Make a frequency table of the data. 6, 7, 14, 12, 13, 14, 16, 16, 17, 17, 19, 21, 26, 12, 12, 13, 15, 15, 20, 20, 24, 10, 12, 15, 16, 17, 17, 18, 20 number of times something occurs A type of display that groups data into intervals to show frequencies. Intervals should be equal. Divide the range of the data by the number of intervals you want the table to have (usually 4-7). Use the quotient as an appropriate interval size. to record the interval in which each data value falls. for each interval by counting the number of tally marks for the interval.

Histograms Histograms: Items to note: Histograms combine data The length of the bar The data items There is no space STEPS to making a histogram: 1) SHOW THE INTERVALS 2) DRAW 3) GIVE Bar graphs that show the frequency (number of times) a data item occurs. Example #2 Make a histogram using the frequency table you made above. into intervals of equal sizes; therefore, the bars have equal width. indicates the frequency of the interval. do not overlap. between bars because there are no gaps between intervals. NOTE: Bar Graphs have spaces between their bars. Vertical axis represents the frequency Horizontal axis shows the intervals of the data. from the frequency table on the horizontal axis, and show the frequency on the vertical axis. LABEL APPRORIATELY. a bar to represent the frequency for each interval. the histogram a title.