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Measures of centre

  • measures of centre

    Mode by Paul

    The mode is the most frquent value in a list of values.
    example : 1 ; 5 ; 12 ; 5 ; 3 ; 1 ; 10 ; 1 ; 6 ; 8 ; 1
    -> the mode is 1, we say that the modal value is 1.

    The mode by Camille

    The mode is the most frequent value in a list of values.
    Example : If the list of values is : 2 ; 7 ; 6 ; 10; 8 ; 6 ; 2 ; 6 ; 3 ; 5 ; 6
    The mode is 6.

    Mean by Solen and Luken

    The mean is the addition of all the values divided by the total of the values.
    exemple: 11values ; 1, 1, 2, 3, 4, 4, 4, 5, 7, 9, 9
    (1*2+2+3+4*3+5+7+2*9)/11 = 4.45

    Median by Paul

    The median is the value which split an orderly (from the lowest to the highest) list of values in two esquivalent parts. To have it, we divide by 2 the nomber of values we have :
    1) If the result is a number without a decimal part, the median is situated between this value and the next one in the orderly list.
    example : 2 ; 4 ; 5 ; 5 ; 6 ; 7 ; 8 ; 15
    -> 8 values -> 8/2=4 -> the median is situated between the 4th and the 5th values, here 6.5.

    Mode by Anna and Jeanne (1)

    1) Mode

    The mode of the data is the most represented value.
    Example -> These values are the marks of a student : 19, 12, 13, 12, 12, 16, 13, 12, here the mode is 12 because it is represented 4 times, it means that the student most of time recieve a 12 for his tests.

    Median by Anna and Jeanne (2)

    2) Median

    First of all, the values of the data must be ordered in the increasing order.

    -When there is an odd number of values, the median of the data is the mid-value.
    Example -> These are the marks of a student : 4, 8, 11, 16, 18, here the mid-value is 11, so the median of the student’s marks is 11. It means that he receive as much marks over than under 11.

    -When there is an even number of values, the median of the data is the mid-value between the two mid-values.
    Example -> These values are the marks of a student : 5, 12, 17, 18, 19, 20, here the mid-value is between 17 and 18, it is 17,5, so the median of the student’s marks is 17,5. It means, like before, that he receive as much marks over than under 17,5.

    Mean by Anna and Jeanne (3)

    3) Mean

    The mean of the data is the values multiplied by their frequency and this divided by the sum of the frequencies (= the total number of values).
    Example -> These values are the marks of a student : 6, 12, 12, 14, 18, 20, 20, 20, 20, 20, his mean will be (6 + 12x2 + 14 + 18 + 20x5) : 10 = 16,2.

    We hope our lesson will help you ! ; )

    The mode and the median by Lucile

    The mode:
    The mode is the most frequent value in a list of values.
    Example:
    List of values: 1 ; 1 ; 2 ; 2 ; 3 ; 2 ; 3 ; 1 ; 2
    Here the mode is 2.

    The median :
    The median is the central value when the values arranged in increasing order.
    Example (if the number of value is odd) :
    List of values: 1 ; 3 ; 4 ; 5 ; 7 ; 10; 11 ; 12
    There are 8 values.
    8/2 = 4
    So the median is between the 4th and 5th value. Hence the median is between 5 et 7.
    Example (if the number of value is even) :
    List of values: 5 ; 7 ; 10 ; 11 ; 15
    There are 5 values.
    5/2 = 2.5
    So the median is the 3rd value. Hence the median is 10.

    The mean by Lucile

    The mean :
    The mean is the sum of all values divided by the number of values.
    Example :
    List of value : 7 ; 8 ; 7 ; 6 ; 9 ; 7 ; 8 ; 6
    (7*3+8*2+6*2+9)/8 = 17.125
    The mean is 17.125.

    Mode, Median and the mean by Romane, Remi, Ambre and Thomas

    1) Mode
    In a statistical serie, there are many values and the mode is the most frequent value.
    Example : the age of pupils in a class:
    15;14;16;17;15;15;17;14;16;14;15;15;15;17;15
    The mode is 15
    3)The mean
    The mean it's when we add all the values and we divided by the number of values.
    Example : 5;4;9;3;7
    There are 5 values, we have to add the5 values and divided by 5 to find the mean : 5+4+9+3+7/5=5.6
    5.6 is the mean

    The mode by Louna and Ophélie

    1) The Mode
    The mode is the most frequent value of the data.

    Example: In a survey studying from the number of pets do twenty people have, the results are shown opposite.

    0-2-2-7-3-1-4-0-2-0-5-3-1-1-2-4-2-2-0-3

    The frequency of 0 is four times.
    The frequency of 1 is three times.
    The frequency of 2 is six times.
    The frequency of 3 is three times.
    The frequency of 4 is twice.
    The frequency of 5 is once.
    The frequency of 7 is once.
    → So the mode is 2 because it is the most represented value.

    The median by Louna and Ophélie

    2) The Median

    The median is the central value when the data arranged in increasing order.

    Example: With the same survey of the last example:

    First we have to arrange data in increasing order:
    0-0-0-0-1-1-1-2-2-2-2-2-2-3-3-3-4-4-5-7
    There are 20 values, so it’s an even number of values.
    That’s why the median it’s between the ten values smaller and the ten values higher.
    Therefore, the median it’s between 2 and 2, and 2 + 2 : 2 = 4 : 2 = 2
    So the median value of the data is 2.

    The mean by Louna and Ophélie

    3) The Mean (or the average)

    The mean is the quotient of the sum of all the values by the number of values.

    Example: With the same survey of the last example:

    First we add all values: 0+0+1+1+1+2+2+2+2+2+2+3+3+3+4+4+5+7 = 44
    Then we divide the sum of all values by the number of values: 44 : 20 = 2.2 ≈ 2
    So the mean of the data is each people have around 2 pets.