Based on test data set 1:

People usualy mixed words average and mean and median. Because this word is used in several different ways. Usualy “average” means “arithmetic mean”:

  • > mean(data$age)
    [1] 40.97
    

Median is the value which is directly in the middle if we look at data ordered in ascending order.

  • > median(data$age)
    [1] 41.5
    

Mode is value which appears in data set most often. R has command “mode” but this shows type of variable. Statistical mode we can get this way:

  • > names(sort(-table(data$age)))[1]
    [1] "25"
    
    # explanation:
    > -table(data$age)
    
    18 21 22 24 25 26 28 29 30 31 32 33 34 36 37 38 40 41 42 43 44 45 46 48 49 50 
    -1 -1 -5 -5 -7 -5 -2 -3 -3 -2 -2 -3 -2 -2 -1 -2 -2 -2 -3 -4 -2 -3 -3 -2 -2 -2 
    51 54 55 57 58 59 60 61 62 63 64 65 
    -1 -4 -5 -3 -1 -1 -4 -3 -2 -1 -3 -1 
    
    > sort(-table(data$age))
    
    25 22 24 26 55 43 54 60 29 30 33 42 45 46 57 61 64 28 31 32 34 36 38 40 41 44 
    -7 -5 -5 -5 -5 -4 -4 -4 -3 -3 -3 -3 -3 -3 -3 -3 -3 -2 -2 -2 -2 -2 -2 -2 -2 -2 
    48 49 50 62 18 21 37 51 58 59 63 65 
    -2 -2 -2 -2 -1 -1 -1 -1 -1 -1 -1 -1