The average marks of 10 students in a class was 60 with a standard deviation 4 while the average marks of the other ten students was 40 with a standard deviation 6. If all the 20 students are taken together their standard deviation will be

The average marks of 10 students in a class was 60 with standard deviation 4. While the average marks of other 10 students was 40 with a standard deviation 6. If all the 20 students are taken together,their standard deviation will be

The average marks of 10 students is 30 if 6 marks is added with each students' marks.Then find the new average.

The marks of 20 students in an examination are given in the following table. Average marks of these student is:

The marks of 10 students in a class are 38, 70, 48,34 ,42, 55 63, 46, 54,44. Find the standard deviation of these marks.

The average marks of 39 students of a class is 50. The marks obtained by 40th student are 39 more than the average marks of all the 40 student are 39 more than the average marks of all the 40 students. Find the mean marks of all the 40 students.

The standard deviation is ….. To the mean deviation taken from the arithmetic mean

Find out the standard deviation of the marks secured by 10 students:

The average marks obtained by the students in a class are 43. If the average marks obtained by 25 boys are 40 and the average marks obtained by the girl students are 48, then what is the number of girl students in the class?