Monday, November 5

Frequency table examples


Frequency is the digit of occurrence of a repeat the  event per unit time it is also called temporal frequency. The time period of one cycle in a repeat the event, so the period is the the same of the frequency.
Frequency of waves

Frequency  is  inverse of the concept of wavelength, simply, frequency is inversely proportional to wavelength λ . The frequency f is the same to the phase velocity v of the wave divided by the wavelength λ of the wave:
   f=v/λ, then v=c   f=c/λ

Other Types of Frequency Table Examples:

The Angular frequency ω is define the rate of alteration in the orientation slant, or in the phase of a sinusoidal waveform
Angular frequency is considered in radians per second (rad/s).
The  frequency is analogous to sequential frequency, but the time axis is replace the one or more spatial displacement axis.
Examples on Frequency Table

Consider the frequency distribution shown in scores of 35 students in a mathematics test.

The mean of these scores = total scores /number of boys

 One way would be to add the scores of all the 35 boys as separate addends and then divide the sum by 35.It will be quite cumbersome.we can make the task easier by multiplying each score by its frequence and then dividing by the total number of boys.

frequency table:

Scores(s)      frequency(f)

      6 0                 1

      65                  2

      70                  6

      75                  8

      80                  7

      85                  5

      90                  3

      95                  2

     100                  1

                         35

Then,  x = 60*1+65*2+70*6+75*8+80*7+85*5+90*3+95*2+100*1/35

              = 60+130+420+600+560+425+270+190+100/35

              =  2755 / 35

              = 551 / 7

              = 78.71 marks

It is more conveninent to find the products of the scores and the frequencies by adding an extra column to the frequency table and the work as under:



Scores(x)        frequence(f)         (f.x)

    6 0                 1              60

    65                  2              130

    70                  6              420

    75                  8              600

    80                  7              560

    85                  5              425

    90                  3              270

    95                  2              190

   100                  1              100

   Sum                 35              2755

Mean=sum of the fx column/ sum of the f column  

             = 2755/35

             = 551 / 7

             = 78.71 marks

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