Answer:
25
Explanation:
Each of the 16 "ratio units" representing all 80 dancers must stand for ...
(80 dancers)/(16) = 5 dancers
Then 5 "ratio units" representing seventh-grade dancers will stand for ...
5 × 5 dancers = 25 dancers
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Another way to figure this is to write the proportion ...
(seventh-grade dancers)/(all dancers) = 5/16
seventh-grade dancers = (all dancers)×(5/16) = 80×5/16
seventh-grade dancers = 25