Presentation on theme: "Learning Goal: To be able to create and interpret frequency tables."— Presentation transcript:
Learning Goal: To be able to create and interpret frequency tables.
Definition A basic frequency table has two columns One column lists all the categories of data. The other column lists the frequency of each category, which is the number of data values in the category.
The grades on a statistics exam were: A A B C C C B B B A C C C C D F F A A F F C C C B B B A A C D F A A B C C C D A Construct a frequency table.
Definitions The relative frequency of any category is the proportion or percentage of the data values that fall in that category: Relative frequency=(frequency in category)/(total frequency) The cumulative frequency of any category is the number of data values in that category and all preceding categories. Add relative frequency and cumulative frequency to the previous frequency table.
Binning Data When it is impossible or impractical to have a category for every value in a data set, we bin (or group) the data into categories (bins), each covering a range of possible data values. In general, the number of bins should be between 5 and 20. The purpose of binning data is to be able to understand the distribution of the data.
Dog Sled Racing How long does it take to finish the 1161-mile Iditarod Dog Sled Race from Anchorage to Nome, Alaska? Finish times (to the nearest hour) for 57 dogsled teams are shown below: Use bins to construct a frequency table.