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.

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Frequency table with the data binned. Page 93 Copyright © 2009 Pearson Education, Inc.

Dog Sled Racing Use bins to construct a frequency table. 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: 261 271 236 244 279 296 284 299 288 247 256 338 360 341 333 266 287 313 311 307 303 277 283 304 305 290 289 297 332 330 309 328 285 291 295 298 306 315 310 318 320 321 323 324 327 Use bins to construct a frequency table.