If is the mean of

Mean of x₁, x₂, x_3.........x_n =

..............(i)

Now,

)

⇒ _i - =

⇒ = 0.

If the mean of five observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the value of x is

If the mean of x, x + 3, x + 5, x + 7, x + 10 is 9, the mean of the last three observation is

If each observation of a data is increased by 5, then their mean

Let be the mean of x₁, x₂, …., x_n and be the mean of y₁, y₂, …y_n. If is the mean of x₁, x₂, …., x_n, y₁, y₂…, y_n, then = ?