Answer:
about 0.53
Step-by-step explanation:
54% of the insured, or .54×900 = 486 individuals are males. That leaves 900-486 = 414 that are females. 43% of those, or .43×414 = 178 are over 25, so the remainder of the 395 who are over 25 are male.
Since 395 -178 = 217 of the males are over 25, there are 486 -217 = 269 who are under 25. Then the fraction of insureds who are under 25 that are male is ...
269/(900 -395) = 269/505 ≈ 0.53
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It can be useful to make a 2-way table from the given information.