Question

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

Let x̄ be the mean of x₁, x₂, ... , xₙ and ȳ the mean of y₁, y₂, ... , yₙ. If z̄ is the mean of x₁, x₂, ... , xₙ, y₁, y₂, ... , yₙ, then z̄ is equal to

If x̄ is the mean of x₁, x₂, ... , xₙ, then for a ≠ 0, the mean of ax₁, ax₂, ..., axₙ, x₁/a, x₂/a, ... , xₙ/a is