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Frequency Distribution with Decimals Here's an example showing how to set up a frequency distribution when the data include decimals: 19.55 20.75 21.28 22.02 22.51 22.55 23.75 24.03 24.24 25.17 25.19 25.7 25.91 26.13 26.13 26.32 26.33 27.01 27.13 27.55 27.57 27.79 28.17 30.46. 30.91 These values were each obtained by taking the average of 25 values randomly chosen between 0 and 50 (i.e., 625 random numbers were used). Divide the range by the number of classes (let's use 5 in this case): (30.91 – 19.55) / 5 = 2.272 So the class width is 2.28 (round up to the next value, in hundredths). Here's the frequency distribution. I have also included the class boundaries, needed for the histogram, and the midpoints. The boundaries and midpoints should not be rounded off. These midpoints work out to a value in the hundredths; sometimes you need thousandths. Class Limits 19.55–21.82 21.83–24.10 24.11–26.38 26.39–28.66 28.67–30.94 Frequency 3 5 9 6 2 Class Boundaries 19.545–21.825 21.825–24.105 24.105–26.385 26.385–28.665 28.665–30.945 Midpoint 20.685 22.965 25.245 27.525 29.805