declare @t table (i float)
insert into @t(i) values (1.5), (2.08), (2.1), (2.2), (2.5), (1.9), (3)
--select * from @t

declare @k table (d float)
insert into @k(d) values (2), (2.17), (2.45)
--select * from @k

;with t as (
  select *, cast(abs(i-d) as float(24)) [diff]
  from @t
  cross join @k
), res as (
  select *,
  case when diff = min(diff) over(partition by i) then d end [c]
  from t
)
select i, d
from res
where c is not null