Mood's Median Test

Individual Statistics and Confidence Intervals - Individual Statistics

  

Use the table of individual statistics to assess the following properties of your data:

·    N<= - The number of observations for each level of the factor that are less than or equal to the overall median.

·    N> - The number of observations for each level of the factor that are greater than the overall median.

·    Median - The median of the observations for each level. These sample medians provide estimates of the population medians for each level.

·    Q3-Q1 - The interquartile range for each level of the factor (which is, like the variance, a measure of the spread of data). Mood's median test assumes that the population variances for all levels are equal. Thus, if the sample interquartile ranges differ by a lot, you might want to test the data for equality of variances.

·    Overall median - The median of all observations.

Example Output

Mood median test for Weight

Chi-Square = 1.44    DF = 3    P = 0.697

 

                             Individual 95.0% CIs

Temp  N≤  N>  Median  Q3-Q1  ---------+---------+---------+-------

38     4   3    19.0    4.0           (---*---------)

42     3   3    19.0    9.5     (---------*------------------)

46     2   4    22.0    7.3      (-----------------*------------)

50     4   2    18.0    4.3  (---------*-------)

                             ---------+---------+---------+-------

                                   17.5      21.0      24.5

 

Overall median = 19.0

Interpretation

The results of the fish data analysis indicate that:

·    The median weight for fish is the smallest at 50 degrees F (18.0) and the largest at 46 degrees F (22.0).

·    The interquartile ranges for the different temperatures do not appear to vary enough from each other to be cause for concern.

 

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