Follwing are the marks obtained by 8 students in Statistics.
Calculate the arithmetic mean.
`{:("Marks",15,18,16,45,32,40,30,28):}`

Following are the marks obtained by 20 students in statistics. Find out coefficient of variation of the marks.

The following table gives the marks obtained by some students. Calculate the median marks obtained by the students. {:("Marks",0-5,5-10,10-15,15-20,20-25,25-30,30-35,35-40,40-45),("Number of Students"," "6," "12," "17," "30," "10," "10," "8," "5," "2):}

Find the mean of the marks obtained by 30 students of class IX of a schoo.

Find the mean of the marks obtained by 30 students of class IX of a school. The marks are

The frequency distribution of the marks obtained by 100 students in a test carrying 50 marks is given below. Then the mean is {:("Marks ",0-9,10-19,20-29,30-39,40-49),("No. of students "," "8," "15," "20," "45," "12):}

The following sercies show marks in Statistics of 9 students in Class XI . Find the median marks. {:("Marks",22,16,18,13,15,19,17,20,23):}

The following table shows marks obtained by the students of a class in their test in English: {:("Marks",0-10,10-20,20-30,30-40,40-50),("Number of Students"," "20," "24," "40," "36," "20):} Calculate arithmetic mean using Step-deviation method.