The weight of 7 boys in a group are 52 kg, 57 kg, 55 kg, 60 kg, 54 kg, 59 kg and 55 kg. Find the mean weight of the group.

The marks obtained by 7 students in a group are 340, 180, 260, 164, 56, 275 and 307 respectively. Find the mean marks per student.

Find the mean of the first ten odd numbers.

Find the mean of all the factors of 20.