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.
Answer:
<h2>The circumference is multipled by 4.</h2>
Step-by-step explanation:
The formula of an area of a circle"

The formula of a circumference of a circle:

The area multipled by 16:

The radius has increased fourfold, therefore:

The circumference is multipled by 4.
You can calculate the area and check the circumference:

Calculate the radius:
<em>divide both sides by π</em>

Calculate the circumference of both circles:



9514 1404 393
Explanation:
You can check your answer by making sure that each of the primes you found is actually a prime. (Compare to a list of known primes, for example.) After you have determined your factors are primes, multiply them together to see if the result is 73. If so, you have found the correct prime factorization.
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<em>Additional comment</em>
73 is prime, so its prime factor is 73.
73 = 73