If you havent learnt Sin, Cos yet, let me know, so we can try the other solutions.
Hola !
The answer is = (-4) as in the attachment provided
Hope it helped you
You already got the first two questions right: the group with the highest number of people unemployed / unemployment rate is the one with the highest bar in the respective histogram.
The two graph are related in this sense: take the first age group as reference. We know that 700 people from 16 to 19 are unemployed, and that those people represent 14% of the population, then we know that the 14% of the population between 16 and 19 is 700.
We can deduce that, if x is the number of people between 16 and 19, we have

So, by the relation between the two graphs, we can deduce the total population for each age group.
Add 4 to boh sides
t/5+4-4=9+4
t/5+0=13
t/5=13
times 5/1 both sides
5t/5=5*13
1t=65
t=65