From the following data of the marks obtained by 60 students of a class, calculate the arithmetic mean: The rcader should note carefully that in discrete and continuous frequency distributions the...

Extracted text: From the following data of the marks obtained by 60 students of a class, calculate the arithmetic mean: The rcader should note carefully that in discrete and continuous frequency distributions the total number of observations, i.e., N= the sum of frequency or N = E/. Note : For the sake of clarity and easc of understanding we have used the terms individual observa- tions, discrete series and continuous series throughout the text. However, the reader should be famil- iar with the terms grouped data and ungro:iped data also. Ungrouped data refer to the individual ob- scrvations whereas grouped data refer to the continuous series and the discrete series. Marks No. Students Murks No. of Students 20 50 10 30 12 60 40 20 70 4