Question on average.

Question

a)Monaco b)France c)Switzerland d)Italy

What I know:

$$\text{Average} = \frac{\text{sum of observations}}{\text{total no of observations}}$$

Answer 1

\begin{align} 184 & = \text{average} = \frac{\text{sum of observations}}{\text{number of observations}} \\[12pt] & = \frac{\text{sum of observations from France}+\text{sum of observations from Italy} + \cdots}{\text{number of obervations}} \\[12pt] & = \frac{(\text{population of France}\times 183) + (\text{population of Italy} \times186) + \cdots}{\text{number of obervations}} \end{align} and so on.

Can you work with that and then see if you have further questions?