Write appropriate functions to perform the following on a DataFrame ?

(i) Calculate the sum

(ii) Count the values

(iii) Calculate the average

(iv) Calculate the most repeated value

(v) Calculate the median

(vi) Calculate the standard deviation

(vii) Calculate the variance

(viii) Calculate the maximum value

(ix) Calculate the standard deviation

(x) Calculate the variance

(i) Calculate the sum — sum() function

(ii) Count the values — count() function

(iii) Calculate the average — mean() function

(iv) Calculate the most repeated value — mode() function

(v) Calculate the median — median() function

(vi) Calculate the standard deviation — std() function

(vii) Calculate the variance — var() function

(viii) Calculate the maximum value — max() function

(ix) Calculate the standard deviation — std() function

(x) Calculate the variance — var() function