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Equivalent statements related to Lebesgue measurability

Let (X,@) be a measurable space.
Statement 1:

it is given that for each a in R the set

{x in X | f(x) <= a } is measurable

Statement 2: f is measurable

We need to prove that statement 1 implies 2.

My approach

Since for each a in R the set

{x in X | f(x) <= a } is measurable = intersection of of n from 1 to infinity

complement of {x in X | f(x) > a } is measurable

Since
{x in X | f(x) > a } is measurable, its complement is also measurable

==> f is measurable

Is this a correct approach?

Many thanks for your feedback
(edited 10 months ago)

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