The data below represent the time ( in minute ) taken by 11 persons to have lunch
58, 22 , 34 , 30, 30 , 38 , 46 , 40 , 44 , 42 , 50
a) Calculate the arithmetic mean and the mode of the sample
b) Split the data into quartiles
c) Determine the inter-quartile range
d) Construct a boxplot for this sample
e) Calculate the Z-score for the extreme values to check whether there is any out the sample ( suggestion: to determine the Z score, you need to calculate S )