Compiled Prelim

FREQUENCY DISTRIBUTION AND GRAPHS

Steps:

  1. Identify the class RANGE (by subtracting the lowest value and highest value)

  2. Identify the class WIDTH (by dividing the class range with class intervals)

    • class interval formula: k = 1+3.3log(N

    • round off the value

  3. make a TABLE in this order (C.I, TALLY, F, CB, <CF, >CF)

    • CI - CLASS INTERVAL (Adding the lowest value by the class width until it reaches the highest value)

      D

    • TALLY - COUNTING (counting the values in that parameter)

    • F - FREQUENCY (counting the tally)

    • CB - CLASS BOUNDARY (substracting the lower-class value by 0.5 and adding the higher-class value by .5)

    • <CF - ASCENDING CUMMULATIVE FREQUENCY (Adding the lowest frequency to the f+1 frequency)

    • >CF - DESCENDING CUMMULATIVE FREQUENCY (substracting the total amount of class to the 2nd frequency to 3rd and so fort)

MIDPOINTS - Adding the upper and lower boundaries and diving by 2

MEASURES OF POSITION

Depending on the asked, The formula may change to 4,10,100

Steps:

  1. Solve for K n/4 (depending on the given it could be K n/4, K n/10, K n/100)

    • K = Position

    • N = Number of classes

  2. Find the nearest higher value and box it so you wont get confused

  3. Find the value of

    • LCBQk (lower class boundary of that class

    • <CQk-1 (Cummulative Frequency of the class before that class)

    • FQk (Frequency of that class)

    • C (Class Interval)

  4. Solve for the formula

MEASURES OF CENTRAL TENDENCY

Mean

Median

  • Steps

    • Find the position by n/2 formula

    • box the class with the nearest highest value

    • Find

      • LCBme (lower class boundary of that class)

      • n/2 (position)

      • <cfme-1 (value of the before cumulative frequency of that class)

      • fme (frequency of that class)

      • c (class interval)

    • Solve for

Mode'

  • Steps

    • Find highest frequency

    • box

    • Find

      • LCBmo (lower class boundary)

        d1 (substract the frequency of the value in the lower class frequency)

      • d2 (substract the frequency of the value in the upper class frequency)

      • c (class interval)'

    • Solve for