DIRECTIONS FOR MAKING FREQUENCY DISTRIBUTION
FOR CONTINUOUS DATA
1. Organize data in ascending order:
1.03
1.36
1.45
1.51
1.63
1.72
1.75
1.85
1.92
1.95
1.99
2.52
2.67
3.06
3.20
3.21
3.47
3.50
3.72
3.78
4.24
4.27
4.43
4.54
4.57
4.58
4.72
4.75
4.79
4.91
2. Determine the number of classes desired (5 to 20):
3. Find the minimum and maximum values:
4. Calculate the Class Width – (max – min)/# of classes and round up to a
convenient number:
5. Pick the Lower Class Limit of the first class – a convenient number below
the minimum:
6. Calculate the Lower Class Limits of the other classes – add the Class Width
to the first Lower Class Limit to get the next Lower Class Limit and so on
(Note – for the limits use the same number of decimal places as the data):
7. Find the Upper Class Limit of the first class – one decimal place less than
the second class’s lower limit:
8. Calculate the other Upper Class Limits – add the Class Width to the first
Upper Class Limit to get the next Upper Class Limit and so on (Note – for
the limits use the same number of decimal places as the data):
9. Split the data into the defined classes and count the frequency in each class:
MAKE THE FREQUENCY DISTRIBUTION BACK AND GRAPH IT.
CLASS
1.00 – 1.69
1.70 – 2.39
2.40 – 3.09
3.10 – 3.79
3.80 – 4.49
4.50 – 5.19
FREQUENCY
Total
30
Be sure this totals to the number of data points:
10. Use the frequency distribution to draw a histogram: