Concept:Each term is obtained by subtracting 4 from the previous term and dividing by 6.Explanation:Check the first step: (252−4)÷6=248÷6=41.33.So the next term should be (41.33−4)÷6=37.33÷6=6.22.But the given third term is 5.22, which is incorrect.Thus 5.22 is the odd number in the series.Answer:The wrong number is 5.22.