If Kimiko is 28, Omi is 2 * 28 years = <<28*2=56>>56 years old.
Arlette is 3/4 * 28 years = <<3/4*28=21>>21 years old.
If you add up their ages, it sums to 21 years + 56 years + 28 years = <<21+56+28=105>>105 years
The average age for the three is 105 years / 3 people = <<105/3=35>>35 years/person
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