cumulative relative frequency

(noun)

the accumulation of the previous relative frequencies

Related Terms

Examples of cumulative relative frequency in the following topics:

  • Relative Frequency Distributions

    • The third column should be labeled Relative Frequency.
    • Just like we use cumulative frequency distributions when discussing simple frequency distributions, we often use cumulative frequency distributions when dealing with relative frequency as well.
    • Cumulative relative frequency (also called an ogive) is the accumulation of the previous relative frequencies.
    • To find the cumulative relative frequencies, add all the previous relative frequencies to the relative frequency for the current row.
    • This graph shows a relative frequency histogram.

  • Frequency

    • Cumulative relative frequency is the accumulation of the previous relative frequencies.
    • To find the cumulative relative frequencies, add all the previous relative frequencies to the relative frequency for the current row.
    • NOTE : Because of rounding, the relative frequency column may not always sum to one and the last entry in the cumulative relative frequency column may not be one.
    • This percentage is the cumulative relative frequency entry in the third row.
    • To find the cumulative relative frequency, add all of the previous relative frequencies to the relative frequency for the current row.

  • Summary

  • Optional Collaborative Classrom Exercise

    • In your class, have someone conduct a survey of the number of siblings (brothers and sisters) each student has.Create a frequency table.Add to it a relative frequency column and a cumulative relative frequency column.Answer the following questions:

  • Practice 1: Center of the Data

    • Exercise 2.11.2: What does the relative frequency column sum to?
    • Exercise 2.11.3: What is the difference between relative frequency and frequency for each data value?
    • Exercise 2.11.4: What is the difference between cumulative relative frequency and relative frequency for each data value?

  • Solutions to Exercises in Chapter 2

    • No. frequency column sums to 18, not 19.
    • Not all cumulative relative frequencies are correct.
    • Frequency for 3 miles should be 1; for 2 miles (left out), 2.
    • Cumulative relative frequency column should read: 0.1052, 0.1579, 0.2105, 0.3684, 0.4737, 0.6316, 0.7368, 0.7895, 0.8421, 0.9474, 1.
    • Rel.Freq.for 1 is 0.3000 and Cum.Rel.Freq.for 1 or less is 0.7500

  • Cumulative Frequency Distributions

    • A cumulative frequency distribution displays a running total of all the preceding frequencies in a frequency distribution.
    • A cumulative frequency distribution is the sum of the class and all classes below it in a frequency distribution.
    • Rather than displaying the frequencies from each class, a cumulative frequency distribution displays a running total of all the preceding frequencies.
    • Constructing a cumulative frequency distribution is not that much different than constructing a regular frequency distribution.
    • The third column should be labeled Cumulative Frequency.

  • Frequency Polygons

    • Frequency polygons are also a good choice for displaying cumulative frequency distributions.
    • A frequency polygon for 642 psychology test scores shown in Figure 1 was constructed from the frequency table shown in Table 1.
    • A cumulative frequency polygon for the same test scores is shown in Figure 2.
    • Since 642 students took the test, the cumulative frequency for the last interval is 642.
    • It is also possible to plot two cumulative frequency distributions in the same graph.

  • Do It Yourself: Plotting Qualitative Frequency Distributions

    • Sometimes a relative frequency distribution is desired.
    • If this is the case, simply add a third column in the table called Relative Frequency.
    • Bar graphs for relative frequency distributions are very similar to bar graphs for regular frequency distributions, except this time, the y-axis will be labeled with the relative frequency rather than just simply the frequency.
    • Since a circle has 360 degrees, this is found out by multiplying the relative frequencies by 360.
    • This graph shows the relative frequency distribution of a bag of Skittles.

  • Guidelines for Plotting Frequency Distributions

    • In statistics, the frequency (or absolute frequency) of an event is the number of times the event occurred in an experiment or study.
    • These frequencies are often graphically represented in histograms.
    • The relative frequency (or empirical probability) of an event refers to the absolute frequency normalized by the total number of events.
    • The height of a rectangle is also equal to the frequency density of the interval, i.e., the frequency divided by the width of the interval.
    • A histogram may also be normalized displaying relative frequencies.