1. Marks secured by a group of 10 students are as follows:

16, 18, 29, 31, 20, 23, 26, 25, 32, 20

i) Find the mean of the data.

ii) If 32 is replaced by 23 in the data, find the new mean.

iii) If each observation in the given data is increased by 5 marks, the what will be the mean?

iv) If two students securing 16 and 32 marks leaves the group, then find the mean of remaining 8 students.