The numbers of children in 10 families of a locality are:

2, 4, 3, 4, 2, 0, 3, 5, 1, 1, 5

Find the mean number of children per family.

Following are the weights (in kg) of 10 new born babies in a hospital on a particular day:

3.4, 3.6, 4.2, 4.5, 3.9, 4.1, 3.8, 4.5, 4.4, 3.6

Find the mean

The percentage of marks obtained by students of a class in mathematics are:

64, 36, 47, 23, 0, 19, 81, 93, 72, 35, 3, 1

Find their mean.

If M is the mean of x₁, x₂, x₃, x₄, x₅ and x₆, prove that

(x₁-M)+ (x₂-M)+ (x₃-M)+ (x₄-M)+ (x₅-M)+(x₆-M) = 0.

Durations of sunshine (in hours) in Amritsar for first 10 days of August 1997 as reported by the Meteorological Department are given below:

9.6, 5.2, 3.5, 1.5, 1.6, 2.4, 2.6, 8.4, 10.3, 10.9

(i) Find the mean

(ii) Verify that = 0