Self-study
Ditrama is a federation made up of three autonomous regions: Korva, Mitro, and Guadar. █████ ███ ███████ ███████████████ █████ ████ ██████ ████████ █ █████ ██ ███████ ████████ █████ ██ ███ █████ ██ ███ █████ ██████████ ██ ███████ ████████ ██ ████ ███████ ██ █████ ██ █ ██████ ██████████ ███████ ████ █████ ███ ██████████ ██ ███████ ████████ █████ ████████ ███ ███ █████ █████████ ████████ ████ ██████ ███ ██████████ ██████ ██ █████ ███ ███████████████ ███ █████ ██████ ████ █████████ ██████████ ███ ██████████
Objective: Make an Inference
The stimulus tells us about a federation called Ditrama, which is made up of the regions Korva, Mitro, and Guadar. The federation's revenue is divided between the regions every year based on their share of the federation's population. So if in a given year Korva had 50 residents, Mitro had 20 residents, and Guadar had 30 residents, then Korva would get 50% of revenue, Mitro would get 20%, and Guadar would get 30%.
Now we learn something a bit surprising: last year, Korva got a decreased share of revenue even though the population increased. But this is only surprising until we consider the difference between numbers and proportions: revenue-sharing is based on the proportion of population in each region, not the raw number of residents. Considering the above example, the revenue division would be the exact same if Korva had 100 residents, Mitro had 40 residents, and Guadar had 60 residents, because the proportions would still be the same.
If Korva received less revenue, that tells us its proportion of the population decreased. And for the proportion of population to decrease even though the number of residents increased, that means the total population of the other two regions must have increased proportionally more than Korva's population. Take the example above, where Korva started with 50 residents, and Mitro plus Guadar together started with 50 residents. If Korva now has 60 residents (a one-fifth increase) but Mitro plus Guadar together have 70 residents (a two-fifths increase), then Korva now has a smaller share of the population despite having an increase in residents.
So that's our inference: the other two provinces, taken together, must have had a proportionally larger increase in population than did Korva. Keep in mind, though, we don't know how this increase is split between Mitro and Guadar. Maybe both of their populations increased, but maybe only one did, by a large enough amount that it still outweighed Korva's increase.
Analysis by AlexandraNash
24.
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a
Of the three ████████ █████ ███ ███ ████████ ██████ ██ ██████████
b
The population of █████ ████ ██ █ ███████ ██████████ ████ ██ ███ ██ ████████ ██████
c
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d
Of the three ████████ █████████ █████████ ████████ ██ ██████████ ███ ███ █████████
e
Korva’s population grew ██ █ ███████ ██████████ ████ ███ ███ ██████████ ██ ██ █████ ███ ██ ███ █████ ███ ██████████ ████████