Yes that's the weight that is needed.

If you weren't given them, you'll have to look them up.

simple example to show why you have to do this.

Suppose country A has 1000 people and 100 are unemployed. That's 10% unemployed.

Suppose country B has 10 people and 9 are unemployed. That's 90% unemployed.

If you just do (10 + 90)/2 = 50, you've given too much importance to country B

You need to go back to the raw data.

Total population = 1000 + 10 = 1010

Total unemployed = 109.

So true average = 109/1010 x 100 = 10.8%

The answer is properly weighted towards the larger population.

Using the formula {(1000 x 10) + (10 x 90)} / 1010 = 10.8

Bob