Grouped Frequency Tables
 

Worked example 2 (continuous data) The monthly rainfall to the nearest mm recorded over a 3 year period is shown below. 6 11 4 4 5 5 21 12 12 13 19 20 24 19 39 14 22 25 24 13 24 30 38 24 29 31 28 42 25 34 23 31 35 50 40

Frequency Tables For continuous data, the measurements can take any value. For example, the first group includes measurements such as 10.2 mm, 10.3 mm, 10.4 mm. (Note, a measurement of 10.5 mm would be rounded up and placed in the next group) We can write the class boundary of the second group in this way. 10.5 <= x < 20.5 This means that the value (x) lies between 10.5 and 20.5. ( Note < means 'less than' and <= means 'less than or equal to') Value Frequency 1 - 10 5 11 - 20 8 21 - 30 13 31 - 40 7 41 - 50 2