Descriptive Statistics:

Descriptive Statistics:

1. collect information about a group of individuals to analyse and draw conclusions

   • Measures of central tendency
     • Mean
       • the average of a dataset
         • Mean = (Sum of all the observations/Total number of observations)
     • Median
       • the midpoint of the data
         • data: 3, 13, 2, 34, 11, 26, 47, the median is 13
     • Mode
       • the most repeated number
         • data: 3, 4, 5, 6, 6, the mode is 6
   • Measures of dispersion
     • Range
       • calculates the difference between the highest and lowest values of.a dataset
         • data: 8, 7, 2, 10, the range is 10-2= 8
     • Interquartile range
       • calculates the spread of the middle 50% of data
         • formula: Q3 - Q1
     • Quartiles
       • Spread of the data set into quarters
         • Q1, Q2, Q3
     • Limit value
       • shows the limit of the values before the atypical values
         • (1.5)(IQR)
           • Lower limit
             • Q1 - LV
           • Upper limit
             • Q3 + LV
   • Measures of the mean
     • variance
       • measures variablity from the mean
         • (∑(xi−mean)^2) / n
     • standard deviation
       • is the square root of the variance