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:
D. $81,728
Step-by-step explanation:
Let's first convert pounds to ounces.
4 pounds x (16 ounces / pound) = <u>64 ounces.</u> (Remember that when we're converting from a larger unit, pounds, to a smaller one, ounces, we'll have more ounces than pounds, so this answer makes sense!)
Let's now get the cost of the gold.
64 oz x ($1277 / oz) = <u>$81,728.</u> (Wow, that's a lot of gold!)