relative frequency

(noun)

the fraction or proportion of times a value occurs

Related Terms

Examples of relative frequency in the following topics:

  • Relative Frequency Distributions

    • The third column should be labeled Relative Frequency.
    • The only difference between a relative frequency distribution graph and a frequency distribution graph is that the vertical axis uses proportional or relative frequency rather than simple frequency.
    • 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.

  • Sampling Distributions and Statistic of a Sampling Distribution

    • You can think of a sampling distribution as a relative frequency distribution with a great many samples.
    • (See Sampling and Data for a review of relative frequency).
    • The results are in the relative frequency table shown below.
    • If you let the number of samples get very large (say, 300 million or more), the relative frequency table becomes a relative frequency distribution.

  • Frequency

    • The sum of the relative frequency column is 20/20 , or 1.
    • 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.
    • To find the relative frequency, divide the frequency by the total number of data values.
    • To find the cumulative relative frequency, add all of the previous relative frequencies to the relative frequency for the current row.

  • 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.

  • Summary

  • Creating a Sampling Distribution

    • The relative frequencies are equal to the frequencies divided by nine because there are nine possible outcomes.
    • The figure below shows a relative frequency distribution of the means.
    • This distribution is also a probability distribution since the $y$-axis is the probability of obtaining a given mean from a sample of two balls in addition to being the relative frequency.
    • After thousands of samples are taken and the mean is computed for each, a relative frequency distribution is drawn.
    • The more samples, the closer the relative frequency distribution will come to the sampling distribution shown in the above figure.

  • Recognizing and Using a Histogram

    • The vertical axis is labeled either frequency or relative frequency.
    • The relative frequency (or empirical probability) of an event refers to the absolute frequency normalized by the total number of events:
    • Put more simply, the relative frequency is equal to the frequency for an observed value of the data divided by the total number of data values in the sample.
    • The height of a rectangle in a histogram is 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.

  • 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.

  • The Doppler Effect

    • The Doppler effect is a periodic event's change in frequency for an observer in motion relative to the event's source.
    • By the time the next wave is emitted, it is closer (relative to an onlooker ahead of the vehicle) to the previous wave than the wave's frequency would suggest.
    • Relative to an onlooker behind the vehicle, the second wave is further from the first wave than one would expect, which suggests a lower frequency.
    • In the example above, the siren moved relative to a stationary observer.
    • Quantitatively, the Doppler effect can be characterized by relating the frequency perceived (f) to the velocity of waves in the medium (c), the velocity of the receiver relative to the medium (vr), the velocity of the source relative to the medium (vs), and the actual emitted frequency (f0):

  • Resonance in RLC Circuits

    • Frequencies at which the response amplitude is a relative maximum are known as the system's resonance frequencies.
    • The reactances vary with frequency $\nu$, with XL large at high frequencies and XC large at low frequencies given as:
    • $\nu_0$ is the resonant frequency of an RLC series circuit.
    • A variable capacitor is often used to adjust the resonance frequency to receive a desired frequency and to reject others. is a graph of current as a function of frequency, illustrating a resonant peak in Irms at $\nu_0 = f_0$.
    • An RLC series circuit with an AC voltage source. f is the frequency of the source.